diff --git a/packages/flutter/lib/material.dart b/packages/flutter/lib/material.dart
index 8f4df1b754b..a2807153f2e 100644
--- a/packages/flutter/lib/material.dart
+++ b/packages/flutter/lib/material.dart
@@ -33,9 +33,11 @@ export 'src/material/material.dart';
 export 'src/material/material_app.dart';
 export 'src/material/material_button.dart';
 export 'src/material/material_list.dart';
-export 'src/material/popup_menu_item.dart';
+export 'src/material/page.dart';
 export 'src/material/popup_menu.dart';
+export 'src/material/popup_menu_item.dart';
 export 'src/material/progress_indicator.dart';
+export 'src/material/radial_reaction.dart';
 export 'src/material/radio.dart';
 export 'src/material/raised_button.dart';
 export 'src/material/scaffold.dart';
@@ -44,11 +46,10 @@ export 'src/material/shadows.dart';
 export 'src/material/snack_bar.dart';
 export 'src/material/switch.dart';
 export 'src/material/tabs.dart';
-export 'src/material/theme_data.dart';
 export 'src/material/theme.dart';
+export 'src/material/theme_data.dart';
 export 'src/material/title.dart';
 export 'src/material/tool_bar.dart';
 export 'src/material/typography.dart';
-export 'src/material/radial_reaction.dart';
 
 export 'widgets.dart';
diff --git a/packages/flutter/lib/src/animation/performance.dart b/packages/flutter/lib/src/animation/performance.dart
index 981e507baa3..879d1c0cf23 100644
--- a/packages/flutter/lib/src/animation/performance.dart
+++ b/packages/flutter/lib/src/animation/performance.dart
@@ -168,7 +168,7 @@ class Performance extends PerformanceView {
 
   /// Returns a [PerformanceView] for this performance,
   /// so that a pointer to this object can be passed around without
-  /// allowing users of that pointer to mutate the AnimationPerformance state.
+  /// allowing users of that pointer to mutate the Performance state.
   PerformanceView get view => this;
 
   /// The length of time this performance should last
diff --git a/packages/flutter/lib/src/material/dialog.dart b/packages/flutter/lib/src/material/dialog.dart
index a4d6e505644..4c041eb091d 100644
--- a/packages/flutter/lib/src/material/dialog.dart
+++ b/packages/flutter/lib/src/material/dialog.dart
@@ -124,7 +124,9 @@ class _DialogRoute extends ModalRoute {
   Duration get transitionDuration => const Duration(milliseconds: 150);
   Color get barrierColor => Colors.black54;
 
-  Widget buildModalWidget(BuildContext context) {
+  Widget buildPage(BuildContext context) => child;
+
+  Widget buildTransition(BuildContext context, PerformanceView performance, Widget child) {
     return new FadeTransition(
       performance: performance,
       opacity: new AnimatedValue<double>(0.0, end: 1.0, curve: Curves.easeOut),
diff --git a/packages/flutter/lib/src/material/material_app.dart b/packages/flutter/lib/src/material/material_app.dart
index 1d35a92bf8a..c34d4da5fb6 100644
--- a/packages/flutter/lib/src/material/material_app.dart
+++ b/packages/flutter/lib/src/material/material_app.dart
@@ -8,6 +8,7 @@ import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 
+import 'page.dart';
 import 'theme.dart';
 import 'title.dart';
 
@@ -95,13 +96,12 @@ class _MaterialAppState extends State<MaterialApp> {
   final HeroController _heroController = new HeroController();
 
   Route _generateRoute(NamedRouteSettings settings) {
-    return new HeroPageRoute(
+    return new MaterialPageRoute(
       builder: (BuildContext context) {
         RouteBuilder builder = config.routes[settings.name] ?? config.onGenerateRoute(settings.name);
         return builder(new RouteArguments(context: context));
       },
-      settings: settings,
-      heroController: _heroController
+      settings: settings
     );
   }
 
@@ -118,7 +118,8 @@ class _MaterialAppState extends State<MaterialApp> {
               title: config.title,
               child: new Navigator(
                 key: _navigator,
-                onGenerateRoute: _generateRoute
+                onGenerateRoute: _generateRoute,
+                observer: _heroController
               )
             )
           )
diff --git a/packages/flutter/lib/src/material/page.dart b/packages/flutter/lib/src/material/page.dart
new file mode 100644
index 00000000000..f4f0fe62e81
--- /dev/null
+++ b/packages/flutter/lib/src/material/page.dart
@@ -0,0 +1,73 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/animation.dart';
+import 'package:flutter/widgets.dart';
+
+class _MaterialPageTransition extends TransitionWithChild {
+  _MaterialPageTransition({
+    Key key,
+    PerformanceView performance,
+    Widget child
+  }) : super(key: key,
+             performance: performance,
+             child: child);
+
+  final AnimatedValue<Point> _position =
+     new AnimatedValue<Point>(const Point(0.0, 75.0), end: Point.origin, curve: Curves.easeOut);
+
+  final AnimatedValue<double> _opacity =
+     new AnimatedValue<double>(0.0, end: 1.0, curve: Curves.easeOut);
+
+  Widget buildWithChild(BuildContext context, Widget child) {
+    performance.updateVariable(_position);
+    performance.updateVariable(_opacity);
+    Matrix4 transform = new Matrix4.identity()
+      ..translate(_position.value.x, _position.value.y);
+    return new Transform(
+      transform: transform,
+      // TODO(ianh): tell the transform to be un-transformed for hit testing
+      child: new Opacity(
+        opacity: _opacity.value,
+        child: child
+      )
+    );
+  }
+}
+
+class MaterialPageRoute extends ModalRoute {
+  MaterialPageRoute({
+    this.builder,
+    NamedRouteSettings settings: const NamedRouteSettings()
+  }) : super(settings: settings) {
+    assert(builder != null);
+    assert(opaque);
+  }
+
+  final WidgetBuilder builder;
+
+  Duration get transitionDuration => const Duration(milliseconds: 150);
+
+  bool get opaque => true;
+
+  Widget buildPage(BuildContext context) {
+    Widget result = builder(context);
+    assert(() {
+      if (result == null)
+        debugPrint('The builder for route \'${settings.name}\' returned null. Route builders must never return null.');
+      assert(result != null && 'A route builder returned null. See the previous log message for details.' is String);
+      return true;
+    });
+    return result;
+  }
+
+  Widget buildTransition(BuildContext context, PerformanceView performance, Widget child) {
+    return new _MaterialPageTransition(
+      performance: performance,
+      child: child
+    );
+  }
+
+  String get debugLabel => '${super.debugLabel}(${settings.name})';
+}
diff --git a/packages/flutter/lib/src/material/popup_menu.dart b/packages/flutter/lib/src/material/popup_menu.dart
index 26af33e6962..c6afa49d4d7 100644
--- a/packages/flutter/lib/src/material/popup_menu.dart
+++ b/packages/flutter/lib/src/material/popup_menu.dart
@@ -110,7 +110,7 @@ class _MenuRoute extends ModalRoute {
   bool get opaque => false;
   Duration get transitionDuration => _kMenuDuration;
 
-  Widget buildModalWidget(BuildContext context) => new _PopupMenu(route: this);
+  Widget buildPage(BuildContext context) => new _PopupMenu(route: this);
 }
 
 Future showMenu({ BuildContext context, ModalPosition position, List<PopupMenuItem> items, int level: 4 }) {
diff --git a/packages/flutter/lib/src/widgets/hero_controller.dart b/packages/flutter/lib/src/widgets/hero_controller.dart
index fb44db96032..3d3bdc63a1d 100644
--- a/packages/flutter/lib/src/widgets/hero_controller.dart
+++ b/packages/flutter/lib/src/widgets/hero_controller.dart
@@ -10,71 +10,49 @@ import 'framework.dart';
 import 'heroes.dart';
 import 'navigator.dart';
 import 'overlay.dart';
-import 'page.dart';
+import 'routes.dart';
 
-class HeroPageRoute extends PageRoute {
-  HeroPageRoute({
-    WidgetBuilder builder,
-    NamedRouteSettings settings: const NamedRouteSettings(),
-    this.heroController
-  }) : super(builder: builder, settings: settings);
-
-  final HeroController heroController;
-  NavigatorState _navigator;
-
-  void didPush(OverlayState overlay, OverlayEntry insertionPoint) {
-    super.didPush(overlay, insertionPoint);
-    // TODO(abarth): Pass the NavigatorState explicitly.
-    if (overlay != null) {
-      _navigator = Navigator.of(overlay.context);
-      heroController?.didPush(_navigator, this);
-    }
-  }
-
-  void didPop(dynamic result) {
-    super.didPop(result);
-    if (_navigator != null) {
-      heroController?.didPop(_navigator, this);
-      _navigator = null;
-    }
-  }
-}
-
-class HeroController {
+class HeroController extends NavigatorObserver {
   HeroController() {
     _party = new HeroParty(onQuestFinished: _handleQuestFinished);
   }
 
   HeroParty _party;
   PerformanceView _performance;
-  HeroPageRoute _from;
-  HeroPageRoute _to;
+  ModalRoute _from;
+  ModalRoute _to;
 
   final List<OverlayEntry> _overlayEntries = new List<OverlayEntry>();
 
-  void didPush(NavigatorState navigator, HeroPageRoute route) {
+  void didPushModal(Route route) {
+    assert(navigator != null);
     assert(route != null);
-    assert(route.performance != null);
-    Route from = navigator.currentRoute;
-    if (from is HeroPageRoute)
-      _from = from;
-    _to = route;
-    _performance = route.performance;
-    _checkForHeroQuest();
-  }
-
-  void didPop(NavigatorState navigator, HeroPageRoute route) {
-    assert(route != null);
-    assert(route.performance != null);
-    Route to = navigator.currentRoute;
-    if (to is HeroPageRoute) {
-      _to = to;
-      _from = route;
+    if (route is ModalRoute) { // as opposed to StateRoute, say
+      assert(route.performance != null);
+      Route from = navigator.currentRoute;
+      if (from is ModalRoute) // as opposed to the many other types of routes, or null
+        _from = from;
+      _to = route;
       _performance = route.performance;
       _checkForHeroQuest();
     }
   }
 
+  void didPopModal(Route route) {
+    assert(navigator != null);
+    assert(route != null);
+    if (route is ModalRoute) { // as opposed to StateRoute, say
+      assert(route.performance != null);
+      Route to = navigator.currentRoute;
+      if (to is ModalRoute) { // as opposed to the many other types of routes
+        _to = to;
+        _from = route;
+        _performance = route.performance;
+        _checkForHeroQuest();
+      }
+    }
+  }
+
   void _checkForHeroQuest() {
     if (_from != null && _to != null && _from != _to) {
       _to.offstage = _to.performance.status != PerformanceStatus.completed;
@@ -123,10 +101,9 @@ class HeroController {
     Set<Key> mostValuableKeys = _getMostValuableKeys();
 
     Map<Object, HeroHandle> heroesFrom = _party.isEmpty ?
-        Hero.of(_from.pageKey.currentContext, mostValuableKeys) : _party.getHeroesToAnimate();
+        Hero.of(_from.subtreeContext, mostValuableKeys) : _party.getHeroesToAnimate();
 
-    BuildContext context = _to.pageKey.currentContext;
-    Map<Object, HeroHandle> heroesTo = Hero.of(context, mostValuableKeys);
+    Map<Object, HeroHandle> heroesTo = Hero.of(_to.subtreeContext, mostValuableKeys);
     _to.offstage = false;
 
     PerformanceView performance = _performance;
@@ -136,7 +113,6 @@ class HeroController {
       curve = new Interval(performance.progress, 1.0, curve: curve);
     }
 
-    NavigatorState navigator = Navigator.of(context);
     _party.animate(heroesFrom, heroesTo, _getAnimationArea(navigator.context), curve);
     _removeHeroesFromOverlay();
     Iterable<Widget> heroes = _party.getWidgets(navigator.context, performance);
diff --git a/packages/flutter/lib/src/widgets/modal_barrier.dart b/packages/flutter/lib/src/widgets/modal_barrier.dart
index 739a710a01a..1f5fe302999 100644
--- a/packages/flutter/lib/src/widgets/modal_barrier.dart
+++ b/packages/flutter/lib/src/widgets/modal_barrier.dart
@@ -2,32 +2,30 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:flutter/animation.dart';
 
 import 'basic.dart';
-import 'focus.dart';
 import 'framework.dart';
 import 'navigator.dart';
-import 'routes.dart';
-import 'status_transitions.dart';
 import 'transitions.dart';
 
-const Color _kTransparent = const Color(0x00000000);
+const Color kTransparent = const Color(0x00000000);
 
 class ModalBarrier extends StatelessComponent {
   ModalBarrier({
     Key key,
-    this.color: _kTransparent
+    this.color: kTransparent,
+    this.dismissable: true
   }) : super(key: key);
 
   final Color color;
+  final bool dismissable;
 
   Widget build(BuildContext context) {
     return new Listener(
       onPointerDown: (_) {
-        Navigator.of(context).pop();
+        if (dismissable)
+          Navigator.of(context).pop();
       },
       child: new ConstrainedBox(
         constraints: const BoxConstraints.expand(),
@@ -45,11 +43,13 @@ class AnimatedModalBarrier extends StatelessComponent {
   AnimatedModalBarrier({
     Key key,
     this.color,
-    this.performance
+    this.performance,
+    this.dismissable: true
   }) : super(key: key);
 
   final AnimatedColorValue color;
   final PerformanceView performance;
+  final bool dismissable;
 
   Widget build(BuildContext context) {
     return new BuilderTransition(
@@ -58,69 +58,12 @@ class AnimatedModalBarrier extends StatelessComponent {
       builder: (BuildContext context) {
         return new IgnorePointer(
           ignoring: performance.status == PerformanceStatus.reverse,
-          child: new ModalBarrier(color: color.value)
+          child: new ModalBarrier(
+            color: color.value,
+            dismissable: dismissable
+          )
         );
       }
     );
   }
 }
-
-class _ModalScope extends StatusTransitionComponent {
-  _ModalScope({
-    Key key,
-    ModalRoute route,
-    this.child
-  }) : route = route, super(key: key, performance: route.performance);
-
-  final ModalRoute route;
-  final Widget child;
-
-  Widget build(BuildContext context) {
-    Widget focus = new Focus(
-      key: new GlobalObjectKey(route),
-      child: new IgnorePointer(
-        ignoring: route.performance.status == PerformanceStatus.reverse,
-        child: child
-      )
-    );
-    ModalPosition position = route.position;
-    if (position == null)
-      return focus;
-    return new Positioned(
-      top: position.top,
-      right: position.right,
-      bottom: position.bottom,
-      left: position.left,
-      child: focus
-    );
-  }
-}
-
-class ModalPosition {
-  const ModalPosition({ this.top, this.right, this.bottom, this.left });
-  final double top;
-  final double right;
-  final double bottom;
-  final double left;
-}
-
-abstract class ModalRoute extends TransitionRoute {
-  ModalRoute({ Completer completer }) : super(completer: completer);
-
-  ModalPosition get position => null;
-  Color get barrierColor => _kTransparent;
-  Widget buildModalWidget(BuildContext context);
-
-  Widget _buildModalBarrier(BuildContext context) {
-    return new AnimatedModalBarrier(
-      color: new AnimatedColorValue(_kTransparent, end: barrierColor, curve: Curves.ease),
-      performance: performance
-    );
-  }
-
-  Widget _buildModalScope(BuildContext context) {
-    return new _ModalScope(route: this, child: buildModalWidget(context));
-  }
-
-  List<WidgetBuilder> get builders => <WidgetBuilder>[ _buildModalBarrier, _buildModalScope ];
-}
diff --git a/packages/flutter/lib/src/widgets/navigator.dart b/packages/flutter/lib/src/widgets/navigator.dart
index 8223aacf412..56a98c55274 100644
--- a/packages/flutter/lib/src/widgets/navigator.dart
+++ b/packages/flutter/lib/src/widgets/navigator.dart
@@ -21,17 +21,26 @@ class NamedRouteSettings {
 
 typedef Route RouteFactory(NamedRouteSettings settings);
 
+class NavigatorObserver {
+  NavigatorState _navigator;
+  NavigatorState get navigator => _navigator;
+  void didPopModal(Route route) { }
+  void didPushModal(Route route) { }
+}
+
 class Navigator extends StatefulComponent {
   Navigator({
     Key key,
     this.onGenerateRoute,
-    this.onUnknownRoute
+    this.onUnknownRoute,
+    this.observer
   }) : super(key: key) {
     assert(onGenerateRoute != null);
   }
 
   final RouteFactory onGenerateRoute;
   final RouteFactory onUnknownRoute;
+  final NavigatorObserver observer;
 
   static const String defaultRouteName = '/';
 
@@ -57,9 +66,24 @@ class NavigatorState extends State<Navigator> {
 
   void initState() {
     super.initState();
+    assert(config.observer == null || config.observer.navigator == null);
+    config.observer?._navigator = this;
     push(config.onGenerateRoute(new NamedRouteSettings(name: Navigator.defaultRouteName)));
   }
 
+  void didUpdateConfig(Navigator oldConfig) {
+    if (oldConfig.observer != config.observer) {
+      oldConfig.observer?._navigator = null;
+      assert(config.observer == null || config.observer.navigator == null);
+      config.observer?._navigator = this;
+    }
+  }
+
+  void dispose() {
+    config.observer?._navigator = null;
+    super.dispose();
+  }
+
   bool get hasPreviousRoute => _modal.length > 1;
   OverlayState get overlay => _overlayKey.currentState;
 
@@ -75,11 +99,7 @@ class NavigatorState extends State<Navigator> {
     return null;
   }
 
-  Route get currentRoute => _ephemeral.isNotEmpty ? _ephemeral.last : _modal.last;
-
-  Route _removeCurrentRoute() {
-    return _ephemeral.isNotEmpty ? _ephemeral.removeLast() : _modal.removeLast();
-  }
+  Route get currentRoute => _ephemeral.isNotEmpty ? _ephemeral.last : _modal.isNotEmpty ? _modal.last : null;
 
   void pushNamed(String name, { Set<Key> mostValuableKeys }) {
     assert(name != null);
@@ -90,9 +110,10 @@ class NavigatorState extends State<Navigator> {
     push(config.onGenerateRoute(settings) ?? config.onUnknownRoute(settings));
   }
 
-  void push(Route route) {
+  void push(Route route, { Set<Key> mostValuableKeys }) {
     _popAllEphemeralRoutes();
     route.didPush(overlay, _currentOverlay);
+    config.observer?.didPushModal(route);
     _modal.add(route);
   }
 
@@ -110,7 +131,13 @@ class NavigatorState extends State<Navigator> {
   }
 
   void pop([dynamic result]) {
-    _removeCurrentRoute().didPop(result);
+    if (_ephemeral.isNotEmpty) {
+      _ephemeral.removeLast().didPop(result);
+    } else {
+      Route route = _modal.removeLast();
+      route.didPop(result);
+      config.observer?.didPopModal(route);
+    }
   }
 
   Widget build(BuildContext context) {
diff --git a/packages/flutter/lib/src/widgets/page.dart b/packages/flutter/lib/src/widgets/page.dart
deleted file mode 100644
index 8833778e8f2..00000000000
--- a/packages/flutter/lib/src/widgets/page.dart
+++ /dev/null
@@ -1,122 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-import 'package:flutter/animation.dart';
-
-import 'basic.dart';
-import 'framework.dart';
-import 'modal_barrier.dart';
-import 'navigator.dart';
-import 'page_storage.dart';
-import 'transitions.dart';
-
-class _PageTransition extends TransitionWithChild {
-  _PageTransition({
-    Key key,
-    PerformanceView performance,
-    Widget child
-  }) : super(key: key,
-             performance: performance,
-             child: child);
-
-  final AnimatedValue<Point> _position =
-     new AnimatedValue<Point>(const Point(0.0, 75.0), end: Point.origin, curve: Curves.easeOut);
-
-  final AnimatedValue<double> _opacity =
-     new AnimatedValue<double>(0.0, end: 1.0, curve: Curves.easeOut);
-
-  Widget buildWithChild(BuildContext context, Widget child) {
-    performance.updateVariable(_position);
-    performance.updateVariable(_opacity);
-    Matrix4 transform = new Matrix4.identity()
-      ..translate(_position.value.x, _position.value.y);
-    return new Transform(
-      transform: transform,
-      child: new Opacity(
-        opacity: _opacity.value,
-        child: child
-      )
-    );
-  }
-}
-
-class _Page extends StatefulComponent {
-  _Page({
-    Key key,
-    this.route
-  }) : super(key: key);
-
-  final PageRoute route;
-
-  _PageState createState() => new _PageState();
-}
-
-class _PageState extends State<_Page> {
-  final GlobalKey _subtreeKey = new GlobalKey();
-
-  Widget build(BuildContext context) {
-    if (config.route._offstage) {
-      return new OffStage(
-        child: new PageStorage(
-          key: _subtreeKey,
-          bucket: config.route._storageBucket,
-          child: _invokeBuilder()
-        )
-      );
-    }
-    return new _PageTransition(
-      performance: config.route.performance,
-      child: new PageStorage(
-        key: _subtreeKey,
-        bucket: config.route._storageBucket,
-        child: _invokeBuilder()
-      )
-    );
-  }
-
-  Widget _invokeBuilder() {
-    Widget result = config.route.builder(context);
-    assert(() {
-      if (result == null)
-        debugPrint('The builder for route \'${config.route.name}\' returned null. Route builders must never return null.');
-      assert(result != null && 'A route builder returned null. See the previous log message for details.' is String);
-      return true;
-    });
-    return result;
-  }
-}
-
-class PageRoute extends ModalRoute {
-  PageRoute({
-    this.builder,
-    this.settings: const NamedRouteSettings()
-  }) {
-    assert(builder != null);
-    assert(opaque);
-  }
-
-  final WidgetBuilder builder;
-  final NamedRouteSettings settings;
-
-  final GlobalKey<_PageState> pageKey = new GlobalKey<_PageState>();
-
-  bool get opaque => true;
-
-  String get name => settings.name;
-  Duration get transitionDuration => const Duration(milliseconds: 150);
-  Widget buildModalWidget(BuildContext context) => new _Page(key: pageKey, route: this);
-
-  final PageStorageBucket _storageBucket = new PageStorageBucket();
-
-  bool get offstage => _offstage;
-  bool _offstage = false;
-  void set offstage (bool value) {
-    if (_offstage == value)
-      return;
-    _offstage = value;
-    pageKey.currentState?.setState(() { });
-  }
-
-  String get debugLabel => '${super.debugLabel}($name)';
-}
diff --git a/packages/flutter/lib/src/widgets/routes.dart b/packages/flutter/lib/src/widgets/routes.dart
index 0cff051a5c4..d43d1210847 100644
--- a/packages/flutter/lib/src/widgets/routes.dart
+++ b/packages/flutter/lib/src/widgets/routes.dart
@@ -7,9 +7,13 @@ import 'dart:async';
 import 'package:flutter/animation.dart';
 
 import 'basic.dart';
+import 'focus.dart';
 import 'framework.dart';
+import 'modal_barrier.dart';
 import 'navigator.dart';
 import 'overlay.dart';
+import 'page_storage.dart';
+import 'status_transitions.dart';
 
 class StateRoute extends Route {
   StateRoute({ this.onPop });
@@ -29,7 +33,7 @@ class OverlayRoute extends Route {
   List<WidgetBuilder> get builders => const <WidgetBuilder>[];
 
   List<OverlayEntry> get overlayEntries => _overlayEntries;
-  final List<OverlayEntry> _overlayEntries = new List<OverlayEntry>();
+  final List<OverlayEntry> _overlayEntries = <OverlayEntry>[];
 
   void didPush(OverlayState overlay, OverlayEntry insertionPoint) {
     for (WidgetBuilder builder in builders) {
@@ -99,3 +103,128 @@ abstract class TransitionRoute extends OverlayRoute {
   String get debugLabel => '$runtimeType';
   String toString() => '$runtimeType(performance: $_performance)';
 }
+
+class _ModalScope extends StatusTransitionComponent {
+  _ModalScope({
+    Key key,
+    this.subtreeKey,
+    this.storageBucket,
+    PerformanceView performance,
+    this.route
+  }) : super(key: key, performance: performance);
+
+  final GlobalKey subtreeKey;
+  final PageStorageBucket storageBucket;
+  final ModalRoute route;
+
+  Widget build(BuildContext context) {
+    Widget contents = new PageStorage(
+      key: subtreeKey,
+      bucket: storageBucket,
+      child: route.buildPage(context)
+    );
+    if (route.offstage) {
+      contents = new OffStage(child: contents);
+    } else {
+      contents = new Focus(
+        key: new GlobalObjectKey(route),
+        child: new IgnorePointer(
+          ignoring: performance.status == PerformanceStatus.reverse,
+          child: route.buildTransition(context, performance, contents)
+        )
+      );
+    }
+    ModalPosition position = route.position;
+    if (position == null)
+      return contents;
+    return new Positioned(
+      top: position.top,
+      right: position.right,
+      bottom: position.bottom,
+      left: position.left,
+      child: contents
+    );
+  }
+}
+
+class ModalPosition {
+  const ModalPosition({ this.top, this.right, this.bottom, this.left });
+  final double top;
+  final double right;
+  final double bottom;
+  final double left;
+}
+
+abstract class ModalRoute extends TransitionRoute {
+  ModalRoute({
+    Completer completer,
+    this.settings: const NamedRouteSettings()
+  }) : super(completer: completer);
+
+  final NamedRouteSettings settings;
+
+
+  // The API for subclasses to override - used by _ModalScope
+
+  ModalPosition get position => null;
+  Widget buildPage(BuildContext context);
+  Widget buildTransition(BuildContext context, PerformanceView performance, Widget child) {
+    return child;
+  }
+
+  // The API for subclasses to override - used by this class
+
+  Color get barrierColor => kTransparent;
+
+
+  // The API for _ModalScope and HeroController
+
+  bool get offstage => _offstage;
+  bool _offstage = false;
+  void set offstage (bool value) {
+    if (_offstage == value)
+      return;
+    _offstage = value;
+    _scopeKey.currentState?.setState(() {
+      // _offstage is the value we're setting, but since there might not be a
+      // state, we set it outside of this callback (which will only be called if
+      // there's a state currently built).
+      // _scopeKey is the key for the _ModalScope built in _buildModalScope().
+      // When we mark that state dirty, it'll rebuild itself, and use our
+      // offstage (via their config.route.offstage) when building.
+    });
+  }
+
+  BuildContext get subtreeContext => _subtreeKey.currentContext;
+
+
+  // Internals
+
+  final GlobalKey<StatusTransitionState> _scopeKey = new GlobalKey<StatusTransitionState>();
+  final GlobalKey _subtreeKey = new GlobalKey();
+  final PageStorageBucket _storageBucket = new PageStorageBucket();
+
+  Widget _buildModalBarrier(BuildContext context) {
+    return new AnimatedModalBarrier(
+      color: new AnimatedColorValue(kTransparent, end: barrierColor, curve: Curves.ease),
+      performance: performance,
+      dismissable: false
+    );
+  }
+
+  Widget _buildModalScope(BuildContext context) {
+    return new _ModalScope(
+      key: _scopeKey,
+      subtreeKey: _subtreeKey,
+      storageBucket: _storageBucket,
+      performance: performance,
+      route: this
+    );
+  }
+
+  List<WidgetBuilder> get builders => <WidgetBuilder>[
+    _buildModalBarrier,
+    _buildModalScope
+  ];
+
+}
diff --git a/packages/flutter/lib/src/widgets/status_transitions.dart b/packages/flutter/lib/src/widgets/status_transitions.dart
index 8b3fe3ae1c4..8af8c307a42 100644
--- a/packages/flutter/lib/src/widgets/status_transitions.dart
+++ b/packages/flutter/lib/src/widgets/status_transitions.dart
@@ -18,10 +18,10 @@ abstract class StatusTransitionComponent extends StatefulComponent {
 
   Widget build(BuildContext context);
 
-  _StatusTransitionState createState() => new _StatusTransitionState();
+  StatusTransitionState createState() => new StatusTransitionState();
 }
 
-class _StatusTransitionState extends State<StatusTransitionComponent> {
+class StatusTransitionState extends State<StatusTransitionComponent> {
   void initState() {
     super.initState();
     config.performance.addStatusListener(_performanceStatusChanged);
diff --git a/packages/flutter/lib/widgets.dart b/packages/flutter/lib/widgets.dart
index da9c32063b7..4c0db2c052c 100644
--- a/packages/flutter/lib/widgets.dart
+++ b/packages/flutter/lib/widgets.dart
@@ -27,7 +27,6 @@ export 'src/widgets/modal_barrier.dart';
 export 'src/widgets/navigator.dart';
 export 'src/widgets/overlay.dart';
 export 'src/widgets/page_storage.dart';
-export 'src/widgets/page.dart';
 export 'src/widgets/placeholder.dart';
 export 'src/widgets/routes.dart';
 export 'src/widgets/scrollable.dart';
diff --git a/packages/unit/test/widget/bottom_sheet_test.dart b/packages/unit/test/widget/bottom_sheet_test.dart
index 92113964d5b..9448fe6577c 100644
--- a/packages/unit/test/widget/bottom_sheet_test.dart
+++ b/packages/unit/test/widget/bottom_sheet_test.dart
@@ -37,8 +37,8 @@ void main() {
       // Tap on the the bottom sheet itself to dismiss it
       tester.tap(tester.findText('BottomSheet'));
       tester.pump(); // bottom sheet dismiss animation starts
-      tester.pump(new Duration(seconds: 1)); // animation done
-      tester.pump(new Duration(seconds: 1)); // rebuild frame
+      tester.pump(new Duration(seconds: 1)); // last frame of animation (sheet is entirely off-screen, but still present)
+      tester.pump(new Duration(seconds: 1)); // frame after the animation (sheet has been removed)
       expect(showBottomSheetThenCalled, isTrue);
       expect(tester.findText('BottomSheet'), isNull);
 
diff --git a/packages/unit/test/widget/remember_scroll_position_test.dart b/packages/unit/test/widget/remember_scroll_position_test.dart
index 904ba7123e9..341adc21976 100644
--- a/packages/unit/test/widget/remember_scroll_position_test.dart
+++ b/packages/unit/test/widget/remember_scroll_position_test.dart
@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:flutter/animation.dart';
-import 'package:flutter/widgets.dart';
+import 'package:flutter/material.dart';
 import 'package:test/test.dart';
 
 import 'widget_tester.dart';
@@ -36,9 +36,9 @@ void main() {
         key: navigatorKey,
         onGenerateRoute: (NamedRouteSettings settings) {
           if (settings.name == '/')
-            return new PageRoute(builder: (_) => new Container(child: new ThePositiveNumbers()));
+            return new MaterialPageRoute(builder: (_) => new Container(child: new ThePositiveNumbers()));
           else if (settings.name == '/second')
-            return new PageRoute(builder: (_) => new Container(child: new ThePositiveNumbers()));
+            return new MaterialPageRoute(builder: (_) => new Container(child: new ThePositiveNumbers()));
           return null;
         }
       ));