I like the way this one was different - oh, first it had that two unsub not acting as the should storyline but I do not know - after those flashbacks to past, it was quite clear we only have one, with two voices in his head..
That really looked like something poorly done if that should have been the main surprise of the episode but as it was not - maybe only a misslead if that or to give viewer a feeling they know what is going on - and then it all upside down in the end.
The story was brutal - really bloody kills.. and that computer thing with web cams... really scary but an amazing storyline. But all the excitement in episode, the dynamic and motion.. it did not prepared me for the end - wow... With those few last minutes everything was turned upside down - it was not to know who is unsub but they point was we needed to know it.. in order the end to work. JJ walking into the barn with those killer dogs.. and Reid... oh.. excited about next episode