The theme of the third season of The Wire is politics, and the show follows a young, ambitious councilman who wants to be mayor.
Even though the theme is politics, the show, after a departure during the second season where the focus was on the docks, returns to giving a lot of time to the stories of the drug-dealing characters from Season One.
This time, a police officer sets up an area, that the users dub "Hamsterdam, " where he promises drug sellers and buyers that they won't be arrested. The idea is that this will remove the crime from the corners where the dealers used to hang out. But what the officer is doing is illegal, and when his plan is discovered, there is all sorts of fallout that affects everyone in the show.
My favorite episode of the season is "Middle Ground, " the second to last episode. The stories of the two top drug dealers come to a climax in an ironic plot reminiscent of a Shakespearean tragedy about ambitious princes.
The DVDs contain several commentary tracks and interviews.
As I wrote in my reviews of the previous seasons, I urge you to watch this show from the beginning, from the first episode of Season One. The show is like a novel, with story threads that start from the beginning, so you will miss a lot of the richness if you start watching in the middle.