Walter, Pete and Belly venture into Olivia's subconscious to try and get her back. Broyles expeirences something new, and everyone loses something.
Where to start?
How Olivia's consciousness is manifested was such a surprise I don't want to mention it.
Peter getting it right.
For a moment I thought "Inception" ho hom... thankfully I was very wrong.
This is very brief because I don't want to give anything away. The ending though - that was chilling.