“Good Form” is the fifth episode of Season Three of ABC’s Once Upon a Time. We get Hook’s backstory and we learn why he became a pirate. Peter Pan is truly demonic, and the rougher, tougher Emma is back. It’s all very “Lord of the Flies” in Neverland, as a Lost Boy challenges Henry to a duel with a stick and a knife. While Hook brings the poisoned David along on a quest.