Here’s a knotty little thriller about a “psychic medium” with an eye for the main chance, if not the gift he’d need to take advantage of it. Because if you’re supposed to be able in touch with the spirit world, the one thing you should be able to figure out is when the hustle is up.

Richard Sommer of TV’s “Mad Men” has the title role of “A Crooked Somebody.” He plays Michael, a colorless wannabe with a book out and a gig working the paid seminar circuit, still giving “readings” to small groups when “by this point, John Edward was on TV every night of the week.”

He makes his gripe to his booker and “plant” in these audiences, Chelsea (Joanne Froggatt of “Downton Abbey), a woman he has history with, who now resists his advances.

Michael sees his work as harmless, giving comfort to the bereaved like an AA group leader or a preacher of the laying-on-of-the-hands variety.

His preacher father (Ed Harris) and mother (Amy Madigan, of course) wish he’d find work with more “honor” in it, with Dad seeing his special “gifts of persuasion” — you’ve got to be a fast talker and a faster-thinker to pull this off — as something he should turn towards sales.

But Michael’s birthday party magician years gave him a taste for applause, and the fact that he’s willing to give away his books on occasion, make him feel he’s “helping.”

“Your son loved animals, didn’t he?” he reassures grieving parents. “There’s no more pain, there’s only joy.”

All that changes when he casts the name “Jim” out into an Arizona audience. One guy who won’t own up to knowing a Jim (Clifton Collins Jr.) seems shaken.

And he’s the fellow who clubs Michael in the parking lot and takes him hostage. Dead “Jim” “showed you what happened.” And that means Michael must die. Michael’s protestations that he’s faking it don’t cut it with Nathan.

“You don’t just stop being psychic, I know the real deal when I see it.”

It takes quick thinking to get that knife away from his throat, and even quicker thinking for Michael to figure out a way to turn this situation  — Nathan committed an infamous murder years ago — to his advantage.

Michael has to improvise, wing it, make it up as he goes. “Jim is FURIOUS with you,” gets the killer’s attention. And a road trip at knife-point gives Michael ideas for how he can “solve” this case and get that “Crossing Over” level of success he’s dreamed of.

Sommer plays Michael straight, so there’s no hint of the lovable con artist about this grifter. He’s an “Ace in the Hole” cynic, a “Leap of Faith” hustler not above risking his neck and his manager’s to work this situation to his advantage.

“There are still moves to make here,” he says, repeatedly plotting his course as he goes along.

Collins, an old hand at playing a gullible murderer (“Capote” was his breakthrough film), carries murderous naivete around like baggage. Sommer gives Michael a paper-thin bravado born of desperation.

Director Trevor White is more known as a producer (“Wind River” and “Ingrid Goes West”), and he’s not bad at maintaining suspense in producer/screenwriter Andrew Zilch of Youtube’s “Good Mythical Morning” somewhat predictable script.

One thing good producers have an eye for is casting. The right actors can save directors and make passable scripts something extra. Even when we know where it’s going, really good actors make that stroll down the primrose path an entertaining one.

MPAA Rating: R for language and brief violence

Cast: Richard Sommer, Clifton Collins, Ed Harris, Amy Madigan

Credits:Directed by Trevor White, script by Andrew Zilch. A Vertical release.

Running time: 1:42