Fiery best

Season four of The Shield begins (10 p.m. Tuesday, the FX Network) with a comparatively tame episode centered around a too-easily-solved multiple murder. But don’t fear: The Shield — the grittiest and perhaps best TV cop show ever — hasn’t turned into a cable NYPD Blue where everything’s wrapped up neatly by the final commercial.

Glenn Close, Michael Chiklis and Anthony Anderson in 'The Shield'

Show creator Shawn Ryan uses this first hour to set up storylines that open the way for another provocative season packed with vicious crimes, nearly R-rated sex and language and — most important — characters who develop in surprising ways. By the end of the hour, you’ll be ready for more and wondering: Can Mackey (Michael Chiklis) survive the personnel moves? Does outgoing Capt. Acaveda (Benito Martinez) finally have Mackey neutralized? Will detectives Wims (CCH Pounder) and Wagenbach (Jay Karnes) regain the trust of the D.A.’s Office? How much longer before someone busts a cap in Shane’s (the superb Walton Goggins) ass? There’ll be no spoilers here. You’re just going to have to watch to find out. And be assured that by week three, the series is back to its fiery best — although they do seem to be solving crimes and stamping out gang wars in record time.

This year’s biggest change to The Shield is the addition of Glenn Close as the new captain, Monica Rawling. After the first three episodes, the jury’s still out on Close. She’s playing Rawling no-nonsense but a little passive, and every now and then Close lets loose a smirk that seems out of place. Then again, it may be an I-know-something-you-don’t-know look. When she meets Claudette, whose firm stance against corruption has left her ostracized by the department higher-ups, this exchange ensues:

Rawling: “And you must be Claudette. I’ve heard a lot about you.”

Wims: “I’m sure you have.”

Rawling: “Yeah. But we’ll make it work anyway.”

It’s funny and a little mysterious. Clearly, Close’s character has motivations we don’t yet understand. More important than adding Close are the personnel changes in the squad room. After last season, in which the Strike Team fell apart, only Mackey and Ronnie Gardocki (David Rees Snell) are together — and they’re involved in a six-month, off-the-streets sting to stop a money-laundering operation. Meanwhile, Shane is in vice — a perfect place for his corruption to continue — and Lem (Kenneth Johnson) has moved to juvenile crime. Their interactions — and lack thereof — create the most stirring parts of the new season.