I would not have wanted to be the artist assigned the task of conceiving this movie’s poster. The American is everything the Bourne films are not, but, of course, to signal that would be to discourage millions of potential ticket buyers. So the designer played it safe and gave us George Clooney charging generically ahead, gun in hand.

The image is so not this movie. The second feature from Dutch photographer-turned-filmmaker Anton (Control) Corbijn is the antithesis of a fast-paced, spectacle-filled Hollywood Eurothriller. Rather, it is a supremely unhurried character study in the course of which we learn few of the central character’s secrets, and the dialogue is almost as spare as the action.

There’s a ’70s Antonioni vibe to the picture, likely to try the patience of viewers with short attention spans but provide a welcome breath of fresh air to anyone who found the summer’s testosterone fests dully interchangeable. Clooney, for example, does not play a member of a special-forces unit who was double-crossed by someone in a powerful government agency and now seeks to clear his name.

We don’t even know his name. One minute it’s Jack. The next it’s Edward. For that matter, we’re not sure for whom he works. He could be an agent for the CIA or, just as easily, a professional assassin. All the first moments tell us is that he is, for some reason, being pursued by a heavily armed Swede and has no problem shooting not only the attacker but also the beauty he’s just bedded, since she witnessed the incident. Not the most sympathetic character the actor’s taken on.

Clooney makes occasional calls to a mysterious handler played by Johan Leysen, who instructs him to lie low and await orders in a small Italian village. Then, technically speaking, very little happens for a long time. He drinks coffee in cafés. He has elliptical chats with a sociable priest (Paolo Bonacelli), who senses his mounting inner turmoil. He enjoys the company of a prostitute (Violante Placido). Eventually Leysen calls with an assignment: custom building a high-speed rifle for a beautiful hired gun (Thekla Reuten). Then, believe it or not, even less happens.

Which sounds as though it might be a problem, but it isn’t. We watch the man with no name construct the weapon to detailed specifications, improvising a sound suppressor out of spare auto parts, and the process is almost hypnotic.

Likewise, the scenes in which Clooney and Reuten fake a lakeside picnic to test-fire the device in private. “You chilled the wine?” she asks as he spills it on the grass. “Italian police,” he states matter of factly. “They’d check.” The script, adapted by Rowan Joffe from Martin Booth’s novel A Very Private Gentleman, has no shortage of such marvelous touches.

And, in its final moments, it even has a sudden burst of spy-thriller action, which Corbijn choreographs with convincing finesse. Clooney’s performance in this film will be underrated, I expect, because it is so restrained, because he doesn’t call on his patented charm, and because, hey, he plays a cold-blooded killer. It’s a superb bit of acting, though, and one has to admire him for stepping outside his comfort zone. It was a riskier roll of the dice than anything he’ll ever do as Danny Ocean.