diff --git a/.idea/runConfigurations/server_dart.xml b/.idea/runConfigurations/server_dart.xml
index 04395e78..2c105dbc 100644
--- a/.idea/runConfigurations/server_dart.xml
+++ b/.idea/runConfigurations/server_dart.xml
@@ -1,6 +1,5 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="server.dart" type="DartCommandLineRunConfigurationType" factoryName="Dart Command Line Application" singleton="true" nameIsGenerated="true">
-    <option name="VMOptions" value="--observe" />
     <option name="filePath" value="$PROJECT_DIR$/example_star_wars/bin/server.dart" />
     <option name="workingDirectory" value="$PROJECT_DIR$/example_star_wars" />
     <method />
diff --git a/example_star_wars/lib/src/models/character.dart b/example_star_wars/lib/src/models/character.dart
index 77016070..38c27393 100644
--- a/example_star_wars/lib/src/models/character.dart
+++ b/example_star_wars/lib/src/models/character.dart
@@ -1,5 +1,8 @@
+import 'package:angel_serialize/angel_serialize.dart';
+
 import 'episode.dart';
 
+@serializable
 abstract class Character {
   String get id;
 
diff --git a/example_star_wars/lib/src/models/droid.dart b/example_star_wars/lib/src/models/droid.dart
index f10c85ac..6cc70e66 100644
--- a/example_star_wars/lib/src/models/droid.dart
+++ b/example_star_wars/lib/src/models/droid.dart
@@ -1,8 +1,10 @@
 import 'package:angel_model/angel_model.dart';
+import 'package:angel_serialize/angel_serialize.dart';
 
 import 'character.dart';
 import 'episode.dart';
 
+@serializable
 class Droid extends Model implements Character {
   String name;
   List<Character> friends;
diff --git a/example_star_wars/lib/src/models/human.dart b/example_star_wars/lib/src/models/human.dart
index 1650d609..8e69bab4 100644
--- a/example_star_wars/lib/src/models/human.dart
+++ b/example_star_wars/lib/src/models/human.dart
@@ -1,9 +1,11 @@
 import 'package:angel_model/angel_model.dart';
+import 'package:angel_serialize/angel_serialize.dart';
 
 import 'character.dart';
 import 'episode.dart';
 import 'starship.dart';
 
+@serializable
 class Human extends Model implements Character {
   String name;
   List<Character> friends;
diff --git a/example_star_wars/lib/src/models/starship.dart b/example_star_wars/lib/src/models/starship.dart
index 9a846173..df300055 100644
--- a/example_star_wars/lib/src/models/starship.dart
+++ b/example_star_wars/lib/src/models/starship.dart
@@ -1,5 +1,7 @@
 import 'package:angel_model/angel_model.dart';
+import 'package:angel_serialize/angel_serialize.dart';
 
+@serializable
 class Starship extends Model {
   String name;
   int length;
diff --git a/example_star_wars/lib/star_wars.dart b/example_star_wars/lib/star_wars.dart
index 3e272d83..f85dc14f 100644
--- a/example_star_wars/lib/star_wars.dart
+++ b/example_star_wars/lib/star_wars.dart
@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'dart:math';
 
 import 'package:angel_framework/angel_framework.dart';
 import 'package:angel_graphql/angel_graphql.dart';
@@ -14,37 +15,62 @@ Future configureServer(Angel app) async {
   var droidService = mountService<Droid>(app, '/api/droids');
   var humansService = mountService<Human>(app, '/api/humans');
   var starshipService = mountService<Starship>(app, '/api/starships');
+  var rnd = new Random();
 
   // Create the GraphQL schema.
   // This code uses dart:mirrors to easily create GraphQL types from Dart PODO's.
-  var droidType = convertDartType(Droid);
+  var droidType = convertDartClass(Droid);
   var episodeType = convertDartType(Episode);
-  var humanType = convertDartType(Human);
+  var humanType = convertDartClass(Human);
   var starshipType = convertDartType(Starship);
+  var heroType = new GraphQLUnionType('Hero', [droidType, humanType]);
 
   // Create the query type.
   //
   // Use the `resolveViaServiceIndex` helper to load data directly from an
   // Angel service.
-  var queryType = objectType('StarWarsQuery',
-      description: 'A long time ago, in a galaxy far, far away...',
-      fields: [
-        field(
-          'droids',
-          type: listType(droidType.nonNullable()),
-          resolve: resolveViaServiceIndex(droidService),
-        ),
-        field(
-          'humans',
-          type: listType(humanType.nonNullable()),
-          resolve: resolveViaServiceIndex(humansService),
-        ),
-        field(
-          'starships',
-          type: listType(starshipType.nonNullable()),
-          resolve: resolveViaServiceIndex(starshipService),
-        ),
-      ]);
+  var queryType = objectType(
+    'StarWarsQuery',
+    description: 'A long time ago, in a galaxy far, far away...',
+    fields: [
+      field(
+        'droids',
+        type: listType(droidType.nonNullable()),
+        resolve: resolveViaServiceIndex(droidService),
+      ),
+      field(
+        'humans',
+        type: listType(humanType.nonNullable()),
+        resolve: resolveViaServiceIndex(humansService),
+      ),
+      field(
+        'starships',
+        type: listType(starshipType.nonNullable()),
+        resolve: resolveViaServiceIndex(starshipService),
+      ),
+      field(
+        'hero',
+        type: heroType,
+        resolve: (_, args) async {
+          var allHeroes = [];
+          var allDroids = await droidService.index() as Iterable;
+          var allHumans = await humansService.index() as Iterable;
+          allHeroes..addAll(allDroids)..addAll(allHumans);
+
+          // Ignore the annoying cast here, hopefully Dart 2 fixes cases like this
+          allHeroes = allHeroes
+              .where((m) =>
+                  !args.containsKey('ep') ||
+                  (m['appears_in'].contains(args['ep']) as bool))
+              .toList();
+
+          return allHeroes.isEmpty
+              ? null
+              : allHeroes[rnd.nextInt(allHeroes.length)];
+        },
+      ),
+    ],
+  );
 
   // Finally, create the schema.
   var schema = graphQLSchema(query: queryType);
@@ -60,9 +86,28 @@ Future configureServer(Angel app) async {
   if (!app.isProduction) {
     app.get('/graphiql', graphiQL());
   }
+
+  // Seed the database.
+  var leia = await humansService.create({
+    'name': 'Leia Organa',
+    'appears_in': ['NEWHOPE', 'EMPIRE', 'JEDI'],
+    'total_credits': 520,
+  });
+
+  var hanSolo = await humansService.create({
+    'name': 'Han Solo',
+    'appears_in': ['NEWHOPE', 'EMPIRE', 'JEDI'],
+    'total_credits': 23,
+    'friends': [leia],
+  });
+
+  var luke = await humansService.create({
+    'name': 'Luke Skywalker',
+    'appears_in': ['NEWHOPE', 'EMPIRE', 'JEDI'],
+    'total_credits': 682,
+    'friends': [leia, hanSolo],
+  });
 }
 
-Service mountService<T extends Model>(Angel app, String path) => app.use(
-    path,
-    new TypedService(new MapService(
-        autoIdAndDateFields: false, autoSnakeCaseNames: false))) as Service;
+Service mountService<T extends Model>(Angel app, String path) =>
+    app.use(path, new TypedService(new MapService())) as Service;
diff --git a/graphql_schema/lib/src/object_type.dart b/graphql_schema/lib/src/object_type.dart
index baf59107..85d53263 100644
--- a/graphql_schema/lib/src/object_type.dart
+++ b/graphql_schema/lib/src/object_type.dart
@@ -35,6 +35,22 @@ class GraphQLObjectType
     if (input is! Map)
       return new ValidationResult._failure(['Expected "$key" to be a Map.']);
 
+    if (isInterface) {
+      List<String> errors = [];
+
+      for (var type in possibleTypes) {
+        var result = type.validate(key, input);
+
+        if (result.successful) {
+          return result;
+        } else {
+          errors.addAll(result.errors);
+        }
+      }
+
+      return new ValidationResult<Map<String, dynamic>>._failure(errors);
+    }
+
     var out = {};
     List<String> errors = [];
 
@@ -51,7 +67,8 @@ class GraphQLObjectType
       var field = fields.firstWhere((f) => f.name == k, orElse: () => null);
 
       if (field == null) {
-        errors.add('Unexpected field "$k" encountered in $key.');
+        errors.add(
+            'Unexpected field "$k" encountered in $key. Accepted values on type $name: ${fields.map((f) => f.name).toList()}');
       } else {
         var v = input[k];
         var result = field.type.validate(k.toString(), v);
diff --git a/graphql_server/lib/graphql_server.dart b/graphql_server/lib/graphql_server.dart
index be693929..97088ba6 100644
--- a/graphql_server/lib/graphql_server.dart
+++ b/graphql_server/lib/graphql_server.dart
@@ -181,7 +181,8 @@ class GraphQL {
     var mutationType = schema.mutation;
 
     if (mutationType == null) {
-      throw new GraphQLException.fromMessage('The schema does not define a mutation type.');
+      throw new GraphQLException.fromMessage(
+          'The schema does not define a mutation type.');
     }
 
     var selectionSet = mutation.selectionSet;
@@ -364,7 +365,7 @@ class GraphQL {
       if (fieldType is GraphQLObjectType && !fieldType.isInterface) {
         objectType = fieldType;
       } else {
-        objectType = resolveAbstractType(fieldType, result);
+        objectType = resolveAbstractType(fieldName, fieldType, result);
       }
 
       var subSelectionSet = mergeSelectionSets(fields);
@@ -375,29 +376,46 @@ class GraphQL {
     throw new UnsupportedError('Unsupported type: $fieldType');
   }
 
-  GraphQLObjectType resolveAbstractType(GraphQLType type, result) {
+  GraphQLObjectType resolveAbstractType(String fieldName, GraphQLType type, result) {
     List<GraphQLObjectType> possibleTypes;
 
     if (type is GraphQLObjectType) {
-      possibleTypes = type.possibleTypes;
+      if (type.isInterface) {
+        possibleTypes = type.possibleTypes;
+      } else {
+        return type;
+      }
     } else if (type is GraphQLUnionType) {
       possibleTypes = type.possibleTypes;
     } else {
       throw new ArgumentError();
     }
 
+    var errors = <GraphQLExceptionError>[];
+
     for (var t in possibleTypes) {
       try {
         var validation =
-            t.validate('@root', foldToStringDynamic(result as Map));
+            t.validate(fieldName, foldToStringDynamic(result as Map));
 
         if (validation.successful) {
           return t;
         }
-      } catch (_) {}
+
+        errors
+            .addAll(validation.errors.map((m) => new GraphQLExceptionError(m)));
+      } catch (_, st) {
+        print('Um... $_');
+        print(st);
+      }
     }
 
-    throw new StateError('Cannot convert value $result to type $type.');
+    errors.insert(
+        0,
+        new GraphQLExceptionError(
+            'Cannot convert value $result to type $type.'));
+
+    throw new GraphQLException(errors);
   }
 
   SelectionSetContext mergeSelectionSets(List<SelectionContext> fields) {
diff --git a/graphql_server/lib/introspection.dart b/graphql_server/lib/introspection.dart
index 921d2707..263b2d5c 100644
--- a/graphql_server/lib/introspection.dart
+++ b/graphql_server/lib/introspection.dart
@@ -462,6 +462,8 @@ Iterable<GraphQLType> _fetchAllTypesFromType(GraphQLType type) {
   } else if (type is GraphQLEnumType) {
     types.add(type);
   } else if (type is GraphQLUnionType) {
+    types.add(type);
+
     for (var t in type.possibleTypes) {
       types.addAll(_fetchAllTypesFromType(t));
     }
diff --git a/graphql_server/lib/mirrors.dart b/graphql_server/lib/mirrors.dart
index 4859db0a..a4926df7 100644
--- a/graphql_server/lib/mirrors.dart
+++ b/graphql_server/lib/mirrors.dart
@@ -16,6 +16,11 @@ GraphQLType convertDartType(Type type, [List<Type> typeArguments]) {
   }
 }
 
+/// Shorthand for [convertDartType], for when you know the result will be an object type.
+GraphQLObjectType convertDartClass(Type type, [List<Type> typeArguments]) {
+  return convertDartType(type, typeArguments) as GraphQLObjectType;
+}
+
 final Map<Type, GraphQLType> _cache =
     <Type, GraphQLType>{};