Director Reed Morano keeps her camera tight on star Blake Lively throughout “The Rhythm Section.” The “Handmaid’s Tale” veteran knows where her meal ticket is, knows that Lively is worth halting filming to have a baby or heal up from a hand injury, which delayed this production.

But that pays off handsomely in this generally crackling vengeance thriller. It is a stylish, gloomy blur of close-ups, hand-held chases, the screen retreating in front of Lively as her character stalks, stumbles, sprints and staggers from one moral dilemma to another.

There are quarries to be stalked, to-the-death fights to survive — barely — and a bomb that’s sure to go off.

And the most bracing and realistic (Sorry, “Fast/Furious” fanatics.) car chase since “The Transporter” pounds an exclamation point on the picture. The star may be the star, but here’s an action director who pops off the screen, too.

Lively dresses down and drags us through the moral descent of a young woman whose family died in a plane brought down by a bomb. Winding up in a flophouse London brothel, an addict selling her body for a fix, isn’t rock bottom. Deciding to take the lives of those who planned and carried out the attack that murdered her parents and siblings is a hard decision for any feeling, thinking and once-moral person.

Stephanie goes by “Lisa,” now. The freelance reporter (Raza Jeffrey) who lures her out of the brothel isn’t doing her much of a favor by telling her that crash wasn’t an accident. But the damage is already done.

“You’re another victim. You’re just not dead yet.”

Stephanie/Lisa gets just enough information and cash from the journalist to do what she decides she must. But when she drops in on the bomber, she loses her nerve.

That’s how she ends up in the clutches of reporter Proctor’s “source,” a mysterious ex-operative code-named “B” and located on remote Scottish loch, reachable only by GPS coordinates.

Jude Law brings a fierce brutality to this guy, just a shadow manhandling the interloper in the dark, just two commando boots in Bear Grylls pants standing over her crumbled body, on the floor where he left her.

He wants nothing to do with her caper, has no interest in training her. He keeps cuffing her, knocking her about and testing her. Law does this with such relish you wonder what his shrink would say, him co-starring with a Sienna Miller (his ex) look-alike and all.

“B” is where Stephanie gets the intel, the means and the opportunity to do what she — like Prince Hamlet — knows she must do — murder the murderers. He declares his skepticism — “In the end, you’ll still be you.” She’ll lose her nerve, in other words. But he teaches her to “Get your ‘rhythm section’ under control — sorted.”

“Your heartbeat is the drums. Your breathing is the bass.” Get rhythm. Get calm.

The film’s flash and tension are a great cover for a script that is absurdly reliant on “deus ex machina” (“god in the machine”), that ancient Greek theatrical shortcut to make the implausible plausible.

Here, we’ve got deus MI-6 “training/intel” guy, deus financier, deus ex-CIA fixer in Spain (Sterling K. Brown). The decision to have Stephanie/Lisa take on the guise of a dead Russian assassin is both pointless and wholly illogical. Add that to the list.

But Moran never loses the urgency even when the plot loses the thread. Dashing from London to Spain to Tangier to Marseilles and New York, she punishes Lively almost as much as Law, and her star gives us just enough “I could/would NEVER do that” moments to immerse us in her quest and put us her in shoes.

The lyrics aren’t all that. But in an action film, it’s tempo that matters. “The Rhythm Section” never loses the beat.

MPAA Rating: R for violence, sexual content, language throughout, and some drug use.

Cast: Blake Lively, Jude Law, Sterling K. Brown, Raza Jeffrey and Max Casella

Credits: Directed by Reed Morano, script by Mark Burnell. A Paramount release.

Running time: 1:49