diff --git a/app/assets/javascripts/discourse/models/composer.js b/app/assets/javascripts/discourse/models/composer.js
index efcd437d80d..bce0fc05475 100644
--- a/app/assets/javascripts/discourse/models/composer.js
+++ b/app/assets/javascripts/discourse/models/composer.js
@@ -446,7 +446,6 @@ Discourse.Composer = Discourse.Model.extend({
       title: this.get('title'),
       category: this.get('categoryId'),
       topic_id: this.get('topic.id'),
-      reply_to_post_number: post ? post.get('post_number') : null,
       imageSizes: opts.imageSizes,
       cooked: this.getCookedHtml(),
       reply_count: 0,
@@ -465,11 +464,22 @@ Discourse.Composer = Discourse.Model.extend({
       auto_close_time: Discourse.Utilities.timestampFromAutocloseString(this.get('auto_close_time'))
     });
 
+    if(post) {
+      createdPost.setProperties({
+        reply_to_post_number: post.get('post_number'),
+        reply_to_user: {
+          username: post.get('username'),
+          uploaded_avatar_id: post.get('uploaded_avatar_id')
+        }
+      });
+    }
+
     // If we're in a topic, we can append the post instantly.
     if (postStream) {
       // If it's in reply to another post, increase the reply count
       if (post) {
         post.set('reply_count', (post.get('reply_count') || 0) + 1);
+        post.set('replies', []);
       }
       if (!postStream.stagePost(createdPost, currentUser)) {
 
diff --git a/app/assets/javascripts/discourse/models/post_stream.js b/app/assets/javascripts/discourse/models/post_stream.js
index 4179812ffc5..8b76ddc0857 100644
--- a/app/assets/javascripts/discourse/models/post_stream.js
+++ b/app/assets/javascripts/discourse/models/post_stream.js
@@ -373,7 +373,6 @@ Discourse.PostStream = Em.Object.extend({
 
     // We can't stage two posts simultaneously
     if (this.get('stagingPost')) { return false; }
-
     this.set('stagingPost', true);
 
     var topic = this.get('topic');
@@ -387,12 +386,14 @@ Discourse.PostStream = Em.Object.extend({
     post.setProperties({
       post_number: topic.get('highest_post_number'),
       topic: topic,
-      created_at: new Date()
+      created_at: new Date(),
+      id: -1
     });
 
     // If we're at the end of the stream, add the post
     if (this.get('loadedAllPosts')) {
       this.appendPost(post);
+      this.get('stream').addObject(post.get('id'));
     }
 
     return true;
@@ -408,6 +409,15 @@ Discourse.PostStream = Em.Object.extend({
     if (this.get('loadedAllPosts')) {
       this.appendPost(post);
     }
+    // Correct for a dangling deleted post, if needed
+    // compensating for message bus pumping in new posts while
+    // your post is in transit
+    if(this.get('topic.highest_post_number') < post.get('post_number')){
+      this.set('topic.highest_post_number', post.get('post_number'));
+    }
+    this.get('stream').removeObject(-1);
+    this.get('postIdentityMap').set(-1, null);
+
     this.get('stream').addObject(post.get('id'));
     this.set('stagingPost', false);
   },
@@ -420,16 +430,19 @@ Discourse.PostStream = Em.Object.extend({
     @param {Discourse.Post} the post to undo from the stream
   **/
   undoPost: function(post) {
+    this.get('stream').removeObject(-1);
     this.posts.removeObject(post);
+    this.get('postIdentityMap').set(-1, null);
 
     var topic = this.get('topic');
-
     this.set('stagingPost', false);
 
     topic.setProperties({
       highest_post_number: (topic.get('highest_post_number') || 0) - 1,
       posts_count: (topic.get('posts_count') || 0) - 1
     });
+
+    // TODO unfudge reply count on parent post
   },
 
   /**