Although the gritty cop drama The Shield would become the FX's network longest-running dramatic series during its fourth season, a serious drop in ratings at the end of season three could well have precipitated the show's cancellation. Giving the program a major shot in the arm was the addition of two new regulars, Glenn Close and Anthony Anderson. Close is introduced as Monica Rawling, the new captain of the Farmington District Strike Force and the new (nominal) boss of tough, brutal, and borderline-corrupt Detective Vic Mackey (Michael Chiklis). Rawlings has been appointed to her post after Mackey's former captain and longtime enemy David Aceveda (Benito Martinez) is elected to the city council. Though certainly not enamored of Vic's strong-arm tactics and questionable ethics, Rawling is willing to give the detective a relatively free hand in dealing with the district's most vicious drug dealers. Even so, both Aceveda and Rawling intend to closely monitor Vic's movements, forcing him to play it "straight" (or as straight as he's capable of being) throughout the season. The promotion of Rawlings has a profound effect not only on Vic but also on his fellow detective Claudette Wyms (CCH Pounder), who is bitter over not being promoted to captain herself.
Anthony Anderson is cast as Antwon Mitchell, at once the most formidable and most frustrating adversary that Mackey and his team have ever come up against. Once a powerful drug lord, Mitchell has managed to win release from prison, and is now regarded by many of the power elite as a reformed man, a dedicated community activist. Of course, Vic (and the viewers) known that Mitchell hasn't changed a bit, and in fact is a more dangerous mob leader and drug pusher than he'd been before his arrest thanks to strong ties with the Russian mafia. But to the public at large, Mitchell is virtually a saint, and thus above suspicion when the you-know-what hits the fan. Even when Vic and Rawlings have Mitchell dead to rights, he manages to wriggle out of their clutches, leading Vic to suspect that there's a mole in the ranks of the strike force -- a mole who may or may not be his longtime colleague Shane Vendrell (Walton Goggins). Vic's determination to expose Mitchell heats up after several cops are murdered in a well-planned ambush. In giving Vic a tacit carte blanche to blast Mitchell's operation apart, Rawling puts her own job on the line. Ironically, what ultimately seals Rawling's doom is not her war against drugs, but her fierce determination to bring the city's most heinous child abusers to justice. Bringing Glenn Close and Anthony Anderson to the fold turned out be the best thing that had happened to The Shield in years. The series ended its four season posting its best-ever ratings -- indeed, some of the best ratings in the entire realm of cable television. ~ Hal Erickson, Rovi