Frank was told by Kira directly before Siren's Call about the clone theory. He took it pretty well, but then he failed to save Elena from drowning. The second he sees the list/hears about it from Jessica things will start making sense for him. He'll assume Elena will be coming back and will be validated when she does. Also if he's a clone that means this version of himself didn't lose his family, carry out his revenge, fight Kilgrave, fall in love with Jess, become mayor of a silent village etc etc. It will be oddly comforting for him... until he sees the pods.

Frank will be finding the new schoolhouse and be all over the Campfire log (I'm sure I'll top level him)! Any questions/suggestions/general plotting stuff can go here.