Baltimore Det. Jimmy McNulty finds himself in hot water with his superior Major William Rawls after a drug dealer, D'Angelo Barksdale who is charged with three murders, is acquitted. McNulty knows the judge in question and although it's not his case, he's called into chambers to explain what happened. Obviously key witnesses recanted their police statements on the stand but McNulty doesn't underplay Barksdale's role in at least 7 other murders. When the judge's raises his concerns at the senior levels of the police department, they have a new investigation on their hands. Lt. Cedric Daniels is put in charge with Kima Greggs as the lead detective. As for Barksdale, he finds himself demoted to a low-level dealer after his arrest and he obviously has to prove himself yet again.

Avon takes care of Omar's man Brandon but Wallace, who saw Brandon in the arcade, isn't too comfortable when he sees what they've done to him. Avon gives D'Angelo and Wallace a bonus for their good work. The police meanwhile get authorization to place taps for the pay phones used by D'Angelo and his crew but can only listen in when one of their suspects is using it meaning they'll have to keep the phones under constant observation. McNulty is in a tight spot when Major Rawls gives him a week to report back to his old job. When he realizes the connections McNulty's made in the various shootings, he announces he's going to arrest the Barksdales for murder and threatens to mess up the drug investigation.

Avon, Stringer and Wee-Bey discuss how best to deal with Omar after the attempted hit on Avon, deciding to let him think they want peace, whilst secretly planning to kill him. As such, Omar and Stringer meet for a parley, with security provided by Prop Joe. Meanwhile, Stringer insists on decreasing Avon's visibility in light of the detail's attempt to follow him after the basketball game. An irritable Phelan signs an affidavit for the new phone being used by the pit crew, and Pearlman tells McNulty that he is not up for automatic re-election, possibly because of the feathers he has ruffled due to his involvement with the Barksdale case. D'Angelo tries to understand why Shardene has left him, and after being clean for three days, Bubbles gets some advice from Waylon, before turning to Greggs for support. Meanwhile, McNulty attempts to flip Wallace, and the detail identifies Barksdale's main stash house. However, when Orlando's attempt to purchase weight gets him a lot more than he bargained for, Burrell sees an opportunity for a dangerous undercover operation.

The wire begins to yield information about the Barksdale organization. Stringer and Avon reminisce on how far they have come. McNulty finds the way to a key piece of the puzzle in an unlikely place. Awaiting his fate, Colvin works behind the scenes to shape the outcome of Amsterdam, while protecting his men from possible repercussions. Bubbles considers a new partner.

Poot returns to the corner after a stint in prison--and is welcomed back. Carcetti engages in a testy budget battle with City Council President Campbell, promotes Daniels, and hits a snag in his efforts to relieve Burrell of his duties.

After flexing his muscles around the city, Carcetti faces his first dilemma when a group of ministers protests Herc's mistreatment of one of their own. Randy gets the cold shoulder at school. Omar and Reynaldo pay a menacing visit to Proposition Joe, with their own proposition. Freamon has a revelation at a crime scene that promises to blow the lid off an unsolved mystery.

Season Five premiere. As McNulty and the detail continue staking out Marlo's crew, recently promoted Sergeant Carver is welcomed by a cauldron of discontent from officers coping with unpaid overtime.

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.

Campbell tries to smooth out the transitions in the police department. The newspaper scrambles to confirm surprising news from City Hall, but lose out to the TV media in scooping a high-profile Grand Jury appearance.

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.

With Steintorf ordering Rawls to initiate 'creative' remedies for the rising crime rate, Freamon's vigilance pays off with a promising lead, sending Sydnor and the department into overdrive.

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.