As always, The Shield juggles multiple plotlines with relentless pacing and narrative economy, packing substantial character developments into all 15 of these action-packed episodes. This season's inclusion of a competitive decoy squad offers humor and professional sacrifice, and the pivotal David Mamet-directed episode "Strays" arrives at a shocking conclusion, with Mamet regulars Clark Gregg and Rebecca Pidgeon (Mamet's wife) giving outstanding guest-star performances. Series star Chiklis (whose pugnacious mug dominates the DVD packaging) makes his directorial debut on "Slipknot," and eight episodes include informative, entertaining commentaries by the principal cast and crew. A generous archive of deleted scenes illustrate the agonizing decisions required by the time constraints of episodic TV, and the making-of documentary offers an intimate look at the series' collaborative writing process. With major developments (including a new role for Glenn Close) in store for season 4, these episodes maintain the high standard of provocative drama that loyal Shield fans have come to expect. --Jeff Shannon