Banks and Delahoy discover a store that sells people murder weapons and instructs them on how to dispose of bodies. They set up a sting, and all is going as planned until a battered woman steals some poison from the store. Meanwhile, Davis Nixon asks Casey to get a client's son out of a bogus resisting arrest charge, as a personal favor. Just as Casey gets the man off the hook, Alvarez realizes the guy's the suspect he's looking for in a hit and run case. And when Cole and his fiancé meet with their minister to discuss their wedding, Frank Lutz shows up and asks Cole for a big favor, threatening otherwise to expose their past together.

Cole receives a disturbing call from Lutz, who believes Walsh knows he killed Kowalski and is on his way to Walsh's diner. Lutz poses as a customer and strikes up a conversation with Walsh before pulling a gun and firing. Lutz escapes and Walsh discovers that one stray bullet went through the diner into his apartment, striking Beaumont. Cole fears for his future as Walsh and Casey begin to uncover pieces of his past relationship with Lutz. Meanwhile, Banks continues to be haunted by the number 42 while he and Delahoy investigate a string of bus robberies. One passenger, a clairvoyant, tries to help them catch the robber with her predictions, causing Banks to question whether fate can be stopped.