Starring Liam Neeson, Julianne Moore, and Michelle Dockery. Rated PG. Now playing

Bill Marks (Liam Neeson) hates flying. The take-offs fill him with anxiety, which he can only soothe by clutching a ribbon borrowed from his daughter, and then only after taking shot after shot of booze.

With these predilections, it’s somewhat strange that Marks would take employment as a United States Air Marshall. But it’s a good thing that he does, because Marks is just the sort of dauntless hero who can foil a cabal of extortionists who are killing random passengers during a transatlantic flight.

It’s also a good thing to get Liam Neeson to play Marks. If there are gaps in the terse, tough-guy dialogue written for Marks, they are filled in by Neeson’s seamed visage and sagging shoulders. You don’t need flashbacks to days when life was fun or even tolerable—it’s all there in his grieving eyes.

He’s also still a brawny specimen, plausibly capable of handling much younger foes even after a half-dozen pre-lunch whiskies. And, since he’s in an airplane (the ultimate locked-room mystery setting), there’s no need for a man in his 60s to go running after villains; he can physically annihilate them at his convenience.

Probably for that reason, director Jaume Collet-Serra keeps Marks mainly under psychological threat. Through the course of the movie, he’s let down by his partner and agency, taunted by text messages sent over a theoretically secure line, and even set up as the fall guy of the ingeniously plotted scheme. His only real allies are a chatty passenger and a nerved-up stewardess, played by Julianne Moore and Michelle Dockery, respectively. And even they don’t trust him much.

Near the end of this otherwise tidily efficient thriller, a bad guy takes a time-out from menacing the passengers to hector Marks. Sneering at the very premise of air security, the villain seems on the verge of making an authorial statement about American paranoia.

Luckily, this is a movie not of speeches, but of tidily deployed suspense tricks that should satisfy any thriller fan, except those who are watching it on an airplane.