'You cannot lose if you do not play.' - Marla Daniels.

McNulty feels the heat when a witness who testified against D'Angelo is found murdered. Meanwhile, Greggs is given the lay of the land regarding Avon Barksdale's key players, and Herc, Carver and Prez find big-time trouble at the towers.

"A man must have a code." - Bunk.

Tipped off by the wire, Greggs, Herc, Carver and Freamon make a bust, but the incident makes Avon and Stringer suspicious, leading them to close shop in the Pit. Meanwhile, Bunk and McNulty look for another witness in the Gant slaying and hunt a suspect known as 'Mr. Bird.'

"Come at the king, you best not miss." - Omar.

An unlikely source gives McNulty the tag of a car driven by Stringer Bell. Meanwhile, Greggs and Carver bust a congressional aide carrying dirty cash, but are forced to let him go. Omar earns his 'loose cannon' moniker.

"all in the game..." - Traditional West Baltimore.

Every crew has weak links--including Avon Barksdale's. With the heat turned up in the high-rises, Daniels and McNulty turn to a higher authority in an effort to crack the case wide open. Season finale.

'They can chew you up, but they gotta spit you out.' -- McNulty

Major Valchek gets back at Sobotka for the church gift fiasco, and a feud begins. Valchek ups the ante by asking Deputy Commissioner Burrell for a detail to go after Sobotka. Avon Barksdale continues to run his empire from a prison cell--counseling his nephew D'Angelo and going after a guard who is harassing the organization's convicted hit-man Wee-Bey.

'Don't worry, kid. You're still on the clock.' -- Horseface

Russell tells Sobotka the investigation is over, but, in fact, a port computer is cloned, and when a container goes missing, the detectives follow. Simultaneously, Greggs and Prez tap into a circuit of Russian prostitutes. With two sets of evidence, the detail goes to Pearlman. Neither crime merits wiretap--but a drug connect could give the case legs.

'Business. Always business.' -- The Greek

The Detail has a setback, while Russell and Bunk revisit Philly to look for evidence. Brother Mouzone talks with Stringer Bell about their agreement, leaving Bell to contend with a dissatisfied Avon Barksdale. Bubbles and Johnny pull another caper and McNulty and Greggs return to the Westside, where they discover new connections.

"Don't matter how many times you get burnt, you just keep doin' the same." -- Bodie

A wave of urban reform brings down the notorious Franklin Terrace public housing towers, forcing the Barksdale drug crew to find a new home. Stringer Bell uses a new sales strategy as he awaits Avon's return. McNulty and the Detail look to make a case against Stringer with a wiretap on a drug ring run by Proposition Joe.

"Why you got to go and fuck with the program?" -- Fruit

West Baltimore residents get surprising straight talk at a community meeting from Major Colvin. Bubbles finds gainful employment; Stringer lunches uptown; and Bunk dangles the promise of immunity to a group of corner boys, in exchange for help. Greggs learns how Marlo takes care of business as Bubbles instructs her on the next big thing: disposable cell phones.