Plot: "Just a gangster, I suppose. " -- Avon Barksdale Stringer Bell gets an education in construction management; Bunk uses shoe-leather to catch up with Omar and deliver a searing message; a frustrated Colvin unleashes the troops on the corner boys, ignoring his new edict; Avon sends Cutty and Slim Charles against Marlo; Bubbles refocuses the picture for Greggs