第 4 季 共 13 集
播出时间：2006年9月11日
第 1 集 Boys of Summer
播出时间：2006年9月11日
"Lambs to the slaughter here." - Marcia Donnelly<br />
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Four West Baltimore boys wrestle with what to do with the rest of their summer vacation as the new fall school year approaches. Bodie deals with his corner running slower than usual so he decides to take on a runner. Marlo believes he has finally solved the problem that Stringer could never figure out. Freamon, Greggs, and Sydnor go to Pearlman to see if she will issue City Hall subpoenas. Meanwhile, the mayoral race heats up as Mayor Royce and his primary challenger, Tommy Carcetti each hit campaign trail. Prez begins preparing for his new career in higher education, while McNulty ends up turning down a promotion.
第 2 集 Soft Eyes
播出时间：2006年9月18日
"I still wake up white in a city that ain't." - Carcetti<br />
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In the hopes of possibly saving her job, Pearlman and Freamon continue arguing over the subpoenas, as the election draws closer. Carcetti drops a bombshell on Royce during their televised debate, while Herc makes a shocking discovery about the Mayor himself. Marlo decides to help the young kids in their preparation for school. Namond gets some advice from his father, Wee-Bey. Bubbles decides to bring in an apprentice to help out his business, while Cutty continues his two jobs; landscaping and boxing mentor.
第 3 集 Home Rooms
播出时间：2006年9月25日
"I love the first day, man. Everybody all friendly an' shit." - Namond Brice<br />
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Prez is shocked by his students; Royce strikes back against Carcetti; Rawls begins to gut the major case unit from the inside; Colvin embarks on a new career.
第 4 集 Refugees
播出时间：2006年10月2日
"No one wins. One side just loses more slowly." - Prez<br />
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Freamon and Greggs move to Homicide, while Herc and Dozerman join Marimow in the lackluster Major Crimes Unit. Cutty gets a "custodial" job at Tilghman School picking up truants, but struggles to make progress while trying to mentor Michael. Bubbles works to get Sherrod back in school as an 8th grader. Burrell finds a way to sabotage the state-witness murder investigation before the election, impacting Greggs. Prez's struggles as a teacher continue while Bodie finds himself working for a new "company". Meanwhile, Colvin pitches his pilot program to the middle school and Carcetti meets with a constituency when he knows that they won't support him regardless of what he says. Randy is faced with a dilemma after being busted for his candy scam and Proposition Joe plays Marlo in a high-stakes heist.
第 5 集 Alliances
播出时间：2006年10月9日
"If you with us, you with us." - Chris Partlow<br />
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Commissioner Burrell loses Royce's support; Chris Partlow tries to recruit Michael to become a soldier in Marlo's unit; Dukie shows Randy and the boys that the missing are really dead; Odell Watkins drops his support for Royce and considers an offer from Councilman Carcetti.
第 6 集 Margin of Error
播出时间：2006年10月16日
"Don't try this shit at home." - Norman Wilson<br />
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Carcetti responds to a campaign smear. Randy is accused of a serious transgression. Colvin's special class gets its first enlistees.
第 7 集 Unto Others
播出时间：2006年10月30日
"Aw yeah. That golden rule." - The Bunk<br />
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Omar calls in a favor to the police; Carcetti gets advice from the ex-mayor and then Mayor Royce and his team; Cutty finds out why Spider has been avoiding him and explains to the rest of his boxers that it won't happen again; Prez makes a break through with his students; Herc loses his camera; Greggs solves the Braddock case with soft eyes; Bubbles gets robbed repeatedly and searches for Sherrod; Namond begins to work a package and finds it hard to get suspended from school; Daniels catches Carcetti's eye.
第 8 集 Corner Boys
播出时间：2006年11月6日
"We got our thing, but it's just part of the big thing." - Zenobia<br />
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Prez wants to teach off curriculum. Carcetti visits the Homicide Department and goes on ride-a-longs for drug busts. Colvin and Dr. Parneti's class discuss the Corner Boy rules. Bunk convinces Holley to take another look at the Old Face Andre/Omar Little case. Herc and Dozerman begin shaking down Marlo and his crew as they try to have their surveillance camera returned. Chris Partlow and Snoop look to send the New York crew a message. Marlo asks Proposition Joe to look into Herc. Michael's father comes home, while Namond recruits a lieutenant.
第 9 集 Know Your Place
播出时间：2006年11月13日
"Might as well dump 'em, get another." - Proposition Joe<br />
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Herc and Dozerman search for Little Kevin; Omar gets out of jail; Carcetti has his first meeting with the City Council; Prez and the teachers begin teaching the test; Proposition Joe lets Marlo know Major Crimes is after him; Bubbles looks to Kima and Herc to help him out; Bubbles delivers Little Kevin to Herc; Old Face Andre goes into hiding but Proposition Joe sells him out; Bug's father gets in Michael's face; Michael takes his problems to Marlo; Daniels and Valchek gets promoted; Omar and Renaldo monitor Marlo's activities.
第 10 集 Misgivings
播出时间：2006年11月20日
"World goin' one way, people another." -Poot<br />
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Walker catches Donut boosting cars and teaches him a lesson; Commissioner Burrell gets advice from Senator Davis; Little Kevin has a talk with Marlo and regrets it; Herc ignores Bubbles call and regrets it; the Area Superintendent questions the success of Colvin and Parenti's project class; Senator Davis attempts to con Carcetti; Carver arrests Namond but keeps him out of baby booking; Burrell has the police force juke the numbers with street sweeps; Marlo puts the word out that Randy is a snitch; Elena sees McNulty as a grown up; Chris Partlow and Snoop target Bug's father for Michael.
第 11 集 A New Day
播出时间：2006年11月27日
"You play in dirt, you get dirty." - McNulty<br />
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Randy has trouble with his friends at school, while Carcetti faces a huge dilemma. Meanwhile, Omar visits Proposition Joe, while Freamon reveals a secret.
第 12 集 That's Got His Own
播出时间：2006年12月4日
"That all there is to it?" - Bubbles<br />
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While searching for the missing bodies, Freamon goes around the chain of command after being rebuked by Landsman. Carcetti finds that his promises of raises could be undermined by the school debt, forcing him to consider groveling before the Governor for money to pay it off. Colvin tries to keep his experimental class funded. Bubbles considers taking extreme measures to get rid of the man who continues to steal from him. Prez is concerned about Dukie's academic promotion. Omar orchestrates another big sting while Namond and Cutty get a first-hand taste of the "new" Michael. Carver's promise to look out for Randy ends up looking empty.
第 13 集 Final Grades
播出时间：2006年12月11日
"If animal trapped call 410-844-6286" - Baltimore, traditional<br />
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Burrell tries to help Daniels. Bubbles' big plan backfires and leaves him in big trouble. Colvin tries to find a solution for Namond while Omar makes new plans. McNulty tries to pay back his debt.
