‘American Assassin’ review: Even Michael Keaton can’t save this one

Is that Dylan O’Brien, best known as the baby-faced Thomas in the “Maze Runner” movies, playing the manly hero of “American Assassin”? It sure is, newly scruffy and chiseled in the mold of a hopeful action star. In fact, you have to wonder if O’Brien, 26, can once again play a teenager in next year’s third and final “Maze” movie.

That’s what I kept thinking during “American Assassin” because, frankly, there wasn’t much else to think about. Directed by Dix Hills native Michael Cuesta and based on a novel by Vince Flynn, “American Assassin” has all the potential to be one of those check-your-brain-at-the-door flicks with cool stunts, fast cars and other reliable thrills. Instead, it delivers glum violence from unlikeable characters, and treats its cookie-cutter spy yarn — terrorists, nuke dealers, a doomsday plot — with real-world seriousness. And guess what? You still have to check your brain at the door.

“American Assassin” is the origin story of Flynn’s best-selling creation Mitch Rapp (O’Brien), a CIA superagent. The information we get, however, is minimal. Rapp was a graduate student (area of study: unstated), who took a beach vacation with his fiancee only to watch her die in a mass terrorist shooting (organization: doesn’t matter). Driven by vengeance and possessed of heretofore unrealized espionage skills, Rapp becomes a one-man army and nearly takes down the attack’s mastermind.

That catches the eye of CIA honcho Irene Kennedy (Sanaa Lathan), who teams Rapp with her best trainer, Stan Hurley (Michael Keaton). With Keaton on hand to add a little zing to this bland espionage soup, we ought to be in good shape. Alas, “American Assassin” keeps piling on the clichés, including a pretty Iranian spy named Annika (Shiva Negar) and a supervillain named Ghost (Taylor Kitsch, who looks confusingly similar to O’Brien). Keaton gets in a good line or two, but he can’t carry the whole movie by himself.

With its underwritten script and a non-emoting O’Brien, “American Assassin” would be merely dull, but its attempt to strike an ice-cold, hard-bitten tone about its dopey plot makes the whole thing insufferable. Hang on to your brain and use it for another movie.