The broken wall in Sam's head causes him to have hallucinations, and he has difficulty discerning what's real and what's not. Bobby worries that Dean is beginning to stumble under the weight of fighting and keeping an eye on Sam.

Dean is furious after Sam disappears to follow a lead on a case with clues that are identical to a case Sam solved as a kid. The demon turns out to be Amy, who has been killing low-life thugs and taking their brains for dinner - the same demon Sam found as a kid.