It isn't perfect by all means. Was expecting a much better developed and interesting unsub, 'Criminal Minds' have some great unsubs and often do a great job fleshing them out, making us truly hate them or feel sorry for them. Didn't really feel either of those with this unsub, who came over more bland than threatening and too one-dimensional and shallow. The beginning doesn't immediately draw one in either and feels on the strange and lacking in momentum side.
As always (with a few exceptions like "The Thirteenth Step", "Hopeless" and "The Fight") with 'Criminal Minds', "Empty Planet" looks great, being beautifully shot and made with a lot of style and atmosphere. The music is suitably haunting and melancholic.
The script is intelligent and thought-provoking, while once the momentum gets going the story is very absorbing and makes the most of an initially odd but actually fascinating and beautifully done concept of bringing literature into life. Particularly good are the latter scenes, with an edge of your seat and moving scene with Morgan and Dr Brazier as they try and save her life and the revenge/hostage parts being done with a lot of suspense.
Regarding the team, they are not as warm in chemistry as they usually are (Morgan and Garcia excepted), but are hardly disconnected. They also serve their purpose well in the story and work great together as a team. While there could have been more little character moments and such, the last scene on the jet in particular between Gideon and Morgan is beautifully done.
All the acting is strong, lead and supporting. All in all, a very nicely done if not quite great episode. 8/10 Bethany Cox