diff --git a/Unity/Assets/Yarn Spinner/Code/DialogueRunner.cs b/Unity/Assets/Yarn Spinner/Code/DialogueRunner.cs
index a32b555d7..8f89ba469 100644
--- a/Unity/Assets/Yarn Spinner/Code/DialogueRunner.cs	
+++ b/Unity/Assets/Yarn Spinner/Code/DialogueRunner.cs	
@@ -129,7 +129,7 @@ public void StartDialogue (string startNode)
 			StartCoroutine (RunDialogue (startNode));
 		}
 		
-		IEnumerator RunDialogue (string startNode)
+		IEnumerator RunDialogue (string startNode = "Start")
 		{
 			// Mark that we're in conversation.
 			isDialogueRunning = true;
@@ -173,6 +173,24 @@ IEnumerator RunDialogue (string startNode)
 			// out of a conversation (ie letterboxing going away, etc)
 			isDialogueRunning = false;
 		}
+
+		public void Clear() {
+
+			if (isDialogueRunning) {
+				throw new System.InvalidOperationException("You cannot clear the dialogue system while a dialogue is running.");
+			}
+
+			dialogue.UnloadAll();
+		}
+
+		public void Stop() {
+			dialogue.Stop();
+		}
+
+		public bool NodeExists(string nodeName) {
+			return dialogue.NodeExists(nodeName);
+		}
+
 	}
 
 	// Scripts that can act as the UI for the conversation should subclass this
diff --git a/YarnSpinner/Dialogue.cs b/YarnSpinner/Dialogue.cs
index 8e2cac73b..dfc2a1f09 100644
--- a/YarnSpinner/Dialogue.cs
+++ b/YarnSpinner/Dialogue.cs
@@ -186,7 +186,7 @@ public int LoadString(string text, bool showTokens=false, bool showParseTree=fal
 				throw new InvalidOperationException ("Attempted to load a Yarn program, but no nodes were loaded");
 			}
 
-			program = loader.Compile ();
+
 
 			return nodesLoaded;
 		}
@@ -195,7 +195,6 @@ public int LoadString(string text, bool showTokens=false, bool showParseTree=fal
 		// you'll get a line, command, or set of options.
 		public IEnumerable<Yarn.Dialogue.RunnerResult> Run(string startNode = DEFAULT_START) {
 
-			stopExecuting = false;
 
 			if (LogDebugMessage == null) {
 				throw new YarnException ("LogDebugMessage must be set before running");
@@ -205,6 +204,18 @@ public int LoadString(string text, bool showTokens=false, bool showParseTree=fal
 				throw new YarnException ("LogErrorMessage must be set before running");
 			}
 
+			if (program == null && loader.nodes.Count > 0) {
+				program = loader.Compile();
+			}
+
+			if (program == null) {
+				LogErrorMessage ("Dialogue.Run was called, but no program was loaded. Stopping.");
+				yield break;
+			}
+
+			stopExecuting = false;
+
+
 			var vm = new VirtualMachine (this, program);
 
 			vm.SetNode (startNode);
@@ -245,12 +256,36 @@ public int LoadString(string text, bool showTokens=false, bool showParseTree=fal
 
 
 
+		}
+
+		public void Stop() {
+			stopExecuting = true;
+		}
+
+		public IEnumerable<string> visitedNodes {
+			get {
+				return visitedNodeNames;
+			}
+		}
+
+		// Unloads ALL nodes.
+		public void UnloadAll(bool clearVisitedNodes = true) {
+			if (clearVisitedNodes)
+				visitedNodeNames.Clear();
+
+			program = null;
+			loader.Clear ();
+
 		}
 
 		public String Compile() {
-			var program = loader.Compile();
+			program = loader.Compile();
 			return program.DumpCode (library);
 		}
+
+		public bool NodeExists(string nodeName) {
+			return program.nodes.ContainsKey(nodeName);
+		}
 		
 
 		// The standard, built-in library of functions and operators.
diff --git a/YarnSpinnerTests/Test.cs b/YarnSpinnerTests/Test.cs
index 10c70bbe0..6cfca431d 100644
--- a/YarnSpinnerTests/Test.cs
+++ b/YarnSpinnerTests/Test.cs
@@ -8,6 +8,7 @@ public class Test
 	{
 
 		Yarn.MemoryVariableStore storage = new Yarn.MemoryVariableStore();
+		Yarn.Dialogue dialogue;
 
 		[SetUp()]
 		public void Init()
@@ -15,13 +16,45 @@ public void Init()
 			var newWorkingDir = 
 				System.IO.Path.Combine (Environment.CurrentDirectory, "Tests");
 			Environment.CurrentDirectory = newWorkingDir;
+
+			dialogue = new Yarn.Dialogue (storage);
+
+			dialogue.LogDebugMessage = delegate(string message) {
+				
+				Console.WriteLine (message);
+
+			};
+
+			dialogue.LogErrorMessage = delegate(string message) {
+				Console.ForegroundColor = ConsoleColor.Red;
+				Console.WriteLine (message);
+				Console.ResetColor ();
+			};
+
+			dialogue.library.RegisterFunction ("assert", 1, delegate(Yarn.Value[] parameters) {
+				if (parameters[0].AsBool == false)
+					Assert.Fail ("Assertion failed");
+			});
 		}
 
 		[Test ()]
-		public void TestCase ()
+		public void TestNodeExists ()
 		{
+			
+			dialogue.LoadFile ("Ship.json");
+
+			dialogue.Compile ();
+
+			Assert.True (dialogue.NodeExists ("Sally"));
+
+			// Test clearing everything
+			dialogue.UnloadAll ();
+
+			// Load an empty node
+			dialogue.LoadString("// Test, this is empty");
+			dialogue.Compile ();
 
-			var d = new Yarn.Dialogue (storage);
+			Assert.False (dialogue.NodeExists ("Sally"));
 
 
 		}