Computed property from has many returning undefined - Ember

I have a feed object which hasMany feedTracks, each feedTrack has a track associated with it.

These relationships work successfully, but when I try to use a computed property, something breaks.

on the feed model i have:

secondFeedTrack: computed('feedTracks.[]', function() {
  return this.get('feedTracks').then((feedTracks) => {
    return feedTracks.objectAt(1);
  });
})

when i do I get:

Object { _id: 136, _label: undefined, _state: undefined, _result: undefined, _subscribers: Array[0] }

which isn't nothing, but it doesn't look right.

when i do i get undefined.

What am i doing wrong to not properly get a feedTrack from the computed property?