Spy thriller ‘American Assassin’ delivers furious action fueled by trio of stars: Michael Keaton, Dylan O’Brien, Taylor Kitsch

The spy yarn “American Assassin” gives new meaning to the phrase “all killer, no filler,” as it delivers its action at regular, bloody intervals, with minimal breaks for the messiness of character development.

This adaptation of Vince Flynn’s airport-friendly best-seller opens with a rather nasty example of “fridging” — the story device of killing off a female character as motivation for the lead male character. In this case, it’s in Ibiza where Mitch Rapp (Dylan O’Brien) proposes to his girlfriend, Katrina (Charlotte Vega), only to see her shot dead when a terrorist group machine-guns the beach.

Mitch goes underground, growing his beard and honing his weapons skills, to try to take down the terrorist leader, Adnan Al-Mansur (Shahid Ahmed), who planned the Ibiza attack. Mitch gets into Al-Mansur’s compound and is about to strike when he’s interrupted by a U.S. special forces unit, which does the job instead.

The feds take Mitch into custody, and it’s a senior CIA official, Irene Kennedy (Sanaa Lathan), who sees potential in his thorough, if reckless, mastery of terrorist cells and fighting tactics. Kennedy encourages Mitch to join the CIA’s elite — and, needless to say, super-secret — assassination unit. Whether he has the stuff to make it is up to the unit’s top trainer, the hard-as-nails Stan Hurley (Michael Keaton).

While Hurley trains Mitch and drills into him the mantra that killing at this level can never be personal, the CIA is tracking a plot by Iranian-backed terrorists to gather the components for a nuclear device. But Kennedy and Hurley suspect somebody else is behind the plan: an ex-operative, and Hurley’s former protégé, known now as Ghost (Taylor Kitsch).

Director Michael Cuesta (“Kill the Messenger”) and a quartet of credited screenwriters keep the action — which hops from London to Istanbul to Rome — moving fluidly. There’s the usual amount of technobabble and spy jargon, but it passes unobtrusively as the story gets down to its bloody kill-or-be-killed dynamics.

What makes “American Assassin” worth the trouble is the triad of actors at the story’s core. O’Brien, matured after “The Maze Runner” films, delivers a solid performance as the young fighter seeking his purpose after his girlfriend’s death. Kitsch, who’s had a fair share of roles like Mitch, buries himself convincingly in the psychotic bad-guy role. And Keaton, who’s forgotten more about action movies than either of his co-stars will ever know, adds an element of loose-cannon danger that makes things unpredictable.