Due to the camera at Orlando's, the detail gather enough information to arrest Avon and many of his people, but, with Wallace dead, they are unable to bring charges against Stringer, who's left on the street. However, disgusted that Avon and Stringer had Wallace killed, D'Angelo flips on the entire organization, giving the detail more information than they could have ever hoped for. As Daniels figures out who the snitch is in the unit, Herc is shocked when he is passed over for promotion in favor of Carver, who scored lower on the sergeant's exam. In Philadelphia, Wee-Bey is arrested and gladly admits to murder after murder. Finally figuring out why Avon has been buying vacant properties in the city, Daniels, McNulty, Freamon and Pearlman take their evidence of political involvement to the FBI. Meanwhile, D'Angelo's mother, Brianna (Michael Hyatt), attempts to convince him to stand with the family.

The detail uses satellite technology to its advantage. Bodie is unhappy that Proposition Joe's people are selling on his turf. Valchek visits the FBI in an attempt to get real results on the docks. Ziggy's deal with Double-G goes bad in a big way. Greggs considers motherhood and Prez makes a major blunder.

The detail makes a desperate move. Nick's deceit is in the open, as Sobotka is overwhelmed by bad news. The Greeks confidently ease out of a brief encounter with the detail and Omar's suspicions are validated. The detail hopes to find Vonda's boss. Nick hopes to repair relations with the Greeks and Sobotka is forced to make a difficult choice.

The detail has a setback. Russell and Bunk revisit Philly, looking for evidence. Brother Mouzone talks with Stringer Bell regarding their agreement, leaving Bell to contend with Avon Barksdale. McNulty and Greggs return to the Westside, where they discover new connections. Herc and Carver feel disrespected by fellow officers. Nick tries to come to terms with the Greeks, and himself.

Responding to an officer's call for help, McNulty and Prez turn up the wrong alley with unanticipated results. Cutty is surprised to find help from within Baltimore's power structure for his proposed boxing gym. Omar decides to go it alone against Avon Barksdale and Stringer Bell. Bubbles is wired up and sent into Hamsterdam

Although he tells Sydnor the Davis investigation could be a 'career case,' Freamon keeps a wary eye out for Marlo, who takes care of some unfinished business and strikes a business deal with Barksdale.

Baltimore's renewed police commitment brings fresh recruits to Daniels and McNulty, starting with Carver. Facing a new political challenge, Carcetti is forced to make dangerous political deals.

Carcetti maps out a damage-control scenario with the police brass in the wake of a startling revelation from Pearlman and Daniels. Their choice: clean up the mess...or hide the dirt.