Didn't you see this movie already? Just recently? It had a hunky leading man and a hot supporting actress. He was a highly trained secret agent and she was his sidekick. Dashing man of unlimited cardiovascular endurance desperately seeks someone flighty but plucky but clumsy but brave. She has a great scream and a better bikini bod. He defies gravity and dodges machine-gun fire.

Maybe you haven't seen this movie before. But you've seen an awful lot of them like it. Roy (Tom Cruise) meets June (Cameron Diaz) aboard an otherwise mundane flight out of Wichita, Kan., that ends up bound for international intrigue. Does the film open with a commuter flight because that's its likely destination?

Back to the plot: June gets wrapped up in Roy's top-secret work and must be endlessly rescued. There are some bad good guys and some bad bad guys. Chases, shootouts and martial arts ensue, one after the other. Repeat. The material has been done and done, seriously and in jest, from James Bond to Austin Powers to “The Bourne Identity” and all the comic versions that followed.
“Knight and Day” is definitely on the jest side, though not an outright satire or parody. It was directed by James Mangold (“Walk the Line”), who gives the action a kick and wrings likeable performances out of Cruise and Diaz. The two have a chemistry that was evident in the far more serious “Vanilla Sky.”

Mangold doesn't mire either actor in the smug cynicism that plagues many movies of this sort. Whereas Brangelina smirked and strutted their way across the screen in “Mr. and Mrs. Smith,” Cruise and Diaz are looser and goofier, and it makes for a more enjoyable buffet of comic romaction. Overall the movie hums somewhere in the orbit of a screwball comedy that at least does its audience the courtesy of trying to be fun. Why does it have to be about secret agents, though? Must every movie have explosions? (PG-13) 110 min.