Television-series actors have the unenviable task of repeating the same emotional cues over and over and over again, all while not letting on that in any real-world situation, they’d feel like Bill Murray’s character in Groundhog Day and probably go nuts. Patrick Dempsey once jokingly mentioned during an interview that he’s effectively run out of ways to show longing. (And you thought the hair was the toughest thing for him to get right on Grey’s Anatomy.) Well, I’d have to give the award in this particular category of repetitive freshness to Patricia Arquette on Medium, who has had to convince us over three seasons — and now a fourth, which starts next week — that continually being slammed awake in the middle of the night by terrifying visions of once and/or future murders hasn’t turned her into a sanitarium candidate. But Arquette’s empathetic talents are such that her wife/mother/psychic Allison DuBois has helped reinvent the emotional template for a TV crime solver: She always seems fragilely trapped by her crazy hot line to evil, while ensuring that her wolf-at-the-door powers don’t endanger the suburban normality she’s worked hard to achieve. It’s still one of the best performances on the tube.

Credit must also go to the creative forces behind Medium and Allison’s nightmare sequences, which still serve up the most unnerving visual/aural creeps in prime time — unflashy, cryptically violent half-scenes that shock and misdirect at the same time — and provide plenty of montage-theory weight, so that jump-cutting to Arquette’s umpteenth jolt upright in bed is as heart-poundingly effective as it was at the beginning. Which means maybe Jake Weber, as Allison’s husband, is the real trooper here. How much sleep could he possibly get, either?

MEDIUM | NBC | Mondays, 10 p.m.

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