Sonny, a man who runs a boy's home, calls Dean in after a mysterious death occurs. When Sam wonders how his brother knows Sonny, Dean explains that he spent two months there when he was 16 after being arrested for theft.

Looking to get Dean out of the bunker, Sam finds a case for him and Dean to investigate – people are disappearing into thin air with only their clothes left behind.

Sam is shocked when his childhood imaginary friend Sully makes an unexpected appearance. Sam can’t understand why he’d see Sully now but what’s even more surprising is that Dean can see him, too. Flashbacks reveal young Sam’s friendship with Sully and why he needed him.