 The episode closes with Zack behind bars at the institution, and Sweets keeping his secret.In the Season 4 finale, Zack is considered a suspect when a man is murdered in a popular nightclub owned by Booth and Brennan.Zack is described by Vincent Nigel-Murray as "the type of moron who goes to jail for a murder he didn't commit", suggesting that, on some level, Booth knows Zack is innocent.