By the end of season three of The Wire -- aka HBO‘s best excuse for staying on the air -- one could sense that the show had, in some sense of the word, come to an end. It was certainly clear for a time that HBO executives thought so, having come close to canceling the multifaceted, frighteningly addictive urban drama yet again, as it never pulled anywhere near the kind of ratings that their warhorses like The Sopranos and Sex and the City had. Although plenty of strings were left dangling at the conclusion of episode 37, "Mission Accomplished," a chapter had been definitively closed, with Avon Barksdale back in jail, and his brainy partner Stringer Belle gunned down. Since the two of them had been the impressive foils to the strung-out cops in the Baltimore Major Crimes Unit, their departure seemed to leave a vacuum. With nobody of real consequence running the West Baltimore drug trade (the Barksdales‘ chief rival and replacement, Marlo Stanfield, seems at first nothing more than some punk kid), what would be left that was worth watching?

More than enough, it turns out.

Every season of The Wire has a theme undergirding and propelling the drama, and the fourth time out, co-creators David Simon and Ed Burns (veterans of the city‘s newspaper and police department, respectively) picked a hell of a one: schools. Into the space left by the decrease in serious, long-term crime investigation that had been a hallmark of previous seasons and indeed gave the show its name -- political game-playing gets the Major Crimes Unit essentially disbanded -- the show slots in a whole new batch of new characters without losing them in the mix (an impressive achievement, given that there were already easily some 30 characters of note before season four even began). While at first the quartet of junior-high kids introduced in the first episode seem like a charismatic and interesting group, it takes a number of episodes for their relevance to the primary drama to become horr