     @setState currentBeatmap: beatmap, callback
 
 
-  indexUsers: (usersArray) ->
-    _.keyBy usersArray, (u) => u.id
-
-
   lookupUser: (id) ->
-    @state.users[id]
+    @indexedUsers ?= _.keyBy @state.beatmapsetDiscussion.users.data, 'id'
+
+    @indexedUsers[id]
 
 
   jumpTo: (_e, {id}) ->

    currentBeatmap: initial.beatmapset.data.beatmaps.data[0]
    currentUser: currentUser
    userPermissions: initial.userPermissions
    users: @indexUsers initial.beatmapsetDiscussion.data.users.data
    mode: 'timeline'
    readPostIds: _.chain(initial.beatmapsetDiscussion.data.beatmap_discussions.data)
      .map (d) => d.beatmap_discussion_posts.data.map (r) => r.id

  setBeatmapsetDiscussion: (_e, {beatmapsetDiscussion, callback}) ->
    @setState
      beatmapsetDiscussion: beatmapsetDiscussion
      callback

  setBeatmapset: (_e, {beatmapset, callback}) ->
