Not since Reservoir Dogs has a film’s title done so little to convey to the marquee-gazing prospective ticket buyer a hint as to the movie’s content. It could almost be a marketing test: At this point in a disturbingly dreary summer movie season (and if Hollywood can’t be depended on to generate post-Memorial Day blockbusters, they’re of no use to anyone), everyone is eager to know if any stars can get audiences into theaters on name value alone. That’s why the posters for the film scream “CRUISE” (Tom) and “DIAZ” (Cameron) louder than the title Knight and Day, which I don’t understand even after seeing the movie.

Me, I wouldn’t have gone to see it on the basis of those names alone, but having done so I was pleasantly surprised, at least for the bulk of the movie. That’s because this action comedy found a smart way to make use of Cruise, a star beset by image problems in recent years. Playing a vaguely defined American secret agent who unintentionally sweeps up civilian Diaz into his current escapade, he mutes his standard macho cockiness into a pleasantly low-key unflappability. At least for the first half of the movie, he’s like Peter Falk in the original The In-Laws: reassuring, the picture of professional competence, and just possibly crazy as a loon. He’s the kind of guy you’d like to have guiding you the first time you go skydiving, and given the mayhem surrounding them it makes for a genuinely funny contrast.

It’s too bad that the film isn’t satisfied to stay with that as a hook for this big-budget shoot-’em-up. Director James Mangold, whose wildly inconsistent oeuvre ranges from Copland and Kate and Leopold to Identity and Walk the Line, wants to revive the glossy spirit of Hitchcock’s North by Northwest (though the plot is closer to another late Cary Grant vehicle, Charade). Cruise’s character becomes more standard and the plot stumbles badly after a second act twist that we don’t believe for a moment, leading to a final reel that never regains its footing.

Despite a budget in the $100+ million range, the film features some surprisingly ugly photography, as if it were shot digitally: a pity given the international locations. (Settings: Boston, the Alps, Spain, the Azores, Vienna.) Diaz is getting a little long in the tooth for this kind of role, but she doesn’t have much chance against Cruise who appears to be doing most of his own stunts. All bets are still on Inception, from Dark Knight director Christopher Nolan, to be the biggest hit of the summer; until that opens on July 16, this should brings wavering audiences back to the theaters.

—m. faust

Watch the trailer for Knight and Day