By Ken Tucker
Updated September 25, 2009 at 04:00 AM EDT

Any fears you had that marriage and a baby would dull the sharp edge of Dexter — I admit it, I was worried — have been thoroughly allayed by season 4’s wonderfully swift, witty, and violent start. That sweet little pumpkin-head Harrison is indeed complicating Dexter’s life. Now, like Michael C. Hall’s character, I jump more often when his cell phone rings and it’s Julie Benz’s Rita asking him to come home than when Dexter is actually slaying someone.

The show has a superb new villain in John Lithgow’s Trinity Killer; Lithgow has played bad before, but he’s not copycatting his earlier scoundrels. He uses eerie calm, even when murdering, to give you chills. Also welcome: Keith Carradine’s sly FBI profiler, guaranteed to keep Trinity, Dexter, and former girlfriend Deb all on their toes.

”Wanna know a secret? Daddy kills people,” was Dexter’s heart-slicing line to his newborn in the premiere. For the rest of us, that just makes Dexter more heartwarming. A?

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