“Criminal” is a Kevin Costner vehicle. But he can wait. Let’s say a little prayer of thanks for Ryan Reynolds first.

It’s a sci-fi spy thriller that has the CIA (Gary Oldman, Alice Eve) order a scientist dabbling in memory preservation (Tommy Lee Jones) to save the last things a dying agent (Reynolds) thought about in the head of a psychopathic killer/convict (Costner).

Yeah.

So Costner’s killer is to walk around with Reynolds’ memories tucked into his head, keeping at least a hint of him alive until the CIA can prevent a terrorist from scoring some doomsday technological breakthrough.

It represents the THIRD body-switch movie of Reynolds’ career, after “The Change-Up” and “Self/less.” How did THAT happen?

Thank-you, “Deadpool,” for saving Reynolds from becoming the new Nicolas Cage. Amen.

Reynolds’ Agent Pope in chased and killed in the first scenes in “Criminal.” It’s in London, and the CIA station, led by Oldman speaking Brooklynese, can access all the city’s surveillance cameras and see what is happening. They just can’t stop it.

Amusingly, the CIA doesn’t involve, you know, British intelligence or the London PD. They’ve seen “London Has Fallen.” They know that’s fruitless.

There’s this rich Spanish anarchist (Jordi Molla) who can access those same cameras, and about anything else that routes through a computer. And he’s in pursuit of this one hacker, “The Dutchman,” who has found his way into the American military’s master control button.

You know, the one that allows launching nuclear weapons which could bring down governments, demolish civilization, create anarchy.

Agent Pope was trying to buy off The Dutchman (Michael Pitt), but died before he could deliver him. That has the CIA reel in their scientist (Jones, who physically recoils from this role), a man who can transfer short-term memory to another brain. For the short term.

So there are all these deadlines, ticking clocks, built into the story.

And who is the best candidate for a memory transfer? A brain-damaged psychotic with no empathy, no guilt, “no impulse control.” He’s played by Costner with a kinetic impatience that is the best thing about the movie.

Because you know no sooner has Jericho Stewart undergone this procedure than he escapes and goes rogue — a rude, violent and impulsive American on the loose in London. Those poor limeys.

“Hurt me,” he growls, “I hurt you worse.”

Barging into the front of lines at the coffee shop, speaking French to the barista (because Pope did), cursing strangers and grabbing what he wants. “I’m hungry…I’m taking your van.” Followed by a beating when this or that Brit protests.

Hilarious.

Gal Gadot, the new Wonder Woman, plays Pope’s widow. Because the memories that are the strongest are Pope’s routines — how he lived at home with his wife and daughter, etc.

Costner’s psychotic outbursts are hyper-violent, yet amusing. The chases passably handled. The surveillance camera plot device is played to death, as is the “hero” having to carry out surgery on himself after an injury.

The plot is nonsensical, a script forever breaking its own rules. Go to IMDB.com and read the cast list to see who was edited out and guess if this ever made more sense in a longer cut.

Israeli director Ariel Vroman seemed so promising after his Hollywood debut, “Iceman.” Here, he just flounders, his only contribution was giving a job to his fellow Israeli Gadot in a supporting part.

Costner gives fair value every time he steps on set, and this Jericho fellow is a lot more fun and interesting and noble, even, than he had any right to be.

And Reynolds? Put your money on him hitting his knees tonight and thanking Marvel for that red suit and all those zingers that “Deadpool” gets to deliver. They saved him from duds like this.

MPAA Rating:R for strong violence and language throughout

Cast: Kevin Costner, Gary Oldman, Alice Eve, Gal Gadot, Tommy Lee Jones, Ryan Reynolds
Credits: Directed by Ariel Vroman, script by Douglas Cook, David Weisberg. A Summit release.

Running time: 1:48