Astrid finds a bizarre case by searching for "atypical FBI case reports". Peter, Olivia and Walter investigate a train station devastated by a bomb and trace it to a man with surprising motives. A familiar face returns, Peter shares some of his shady past with Olivia, Walter bonds with Peter and Olivia's Obi-Wan annoys. This was a good, tense ep. Walter mentions a childhood memory that Peter finally shares. Peter reveals he is on a couple of watch lists. Just why did he do? Why did TPTB kill Charlie off? How is Peter able to hold his own in a brawl with a military officer? How much more bonding time do Peter and Walter have left? When will Peter find out that Walter tore him away from everything he knew? Where is Alter-Walter? After all, take away a man's son and he has nothing left to lose. Who wants photos of Walter? Which Walter is in the photos?
"So apart from the obvious, anything out of the ordinary?"
"They've been planning for war."
"Your father has a wonderful voice."
"Not when he's doing jumping jacks and did I mention he was naked?"
"Putting together a jigsaw of a nude centrefold was Walter's idea of how to explain, what was it, human reproduction."
"Four words that should never show up in a sentence. Classified experimental military project."