Valentine's Day (S05E16)
Brodie proposes that his classmate Schack might be involved in the death of a student Munch suspects committed suicide. Meanwhile, Frank and Mary discuss their marital issues during a session with their counselor. Bayliss and Kellerman work to connect two fatal bombings. Schack physically confronts Brodie, but Brodie lacks evidence. He devises a plan to coax a confession from Schack. Frank tells Mary he's willing to have Olivia baptized, but when he arrives late, Mary interprets this as a bad omen and decides to leave him for a while. Mike uncovers a link between the bombings, both tied to the murder of a Korean grocer connected to Luther Mahoney, raising fears of more explosives, particularly at the courthouse where Meldrick and Julianna await a meeting with Judge Aandahl and Danvers.