Marlo maintains discipline without bringing police attention; the mayoral candidates hit different campaign trails in the final weeks of the race; McNulty turns down a promotion.
Valchek leaks details of a case to Carcetti; Royce turns against Burrell; Chris tries to enlist Michael into Marlo's ranks.
Freamon and Greggs move to the homicide unit; Cutty gets a job at Tilghman school; Bubbles gives Sherrod an ultimatum to get back in school.
Herc's job with the mayor takes a hard turn; Prez prepares for his first day as a teacher; Carcetti drops a bombshell on the mayor during a televised debate.
Carcetti makes the rounds with members of the force; Herc tries to retrieve his camera; the return of a missing family member dismays Michael.