Tom Cruise shines, but 'Knight and Day' doesn't

On the long and bumpy road from spec script to development to screen, the action-comedy "Knight and Day" clearly lost a wheel or two. It still manages to wobble across the finish line, thanks mostly to Tom Cruise, who as superspy Roy Miller saves the movie much as he saves the hapless June Havens, played by Cameron Diaz, whenever he appears on screen.

Say what you will about Cruise - and there's so much to say - but the guy is a star. He looks great running across a European rooftop, wears a machine gun well and still boasts a knockout smile. (Next to him, the radiant Diaz is actually believable as an average gal from Boston.) What's more, he never phones it in. Even here, Cruise is at maximum intensity.

But Cruise alone can't turn a Yugo into a Ferrari. Director James Mangold ("3:10 to Yuma"), who co-wrote with Patrick O'Neill, seems aware that the script is hash - the power source, the arms dealer, the rogue agents - and he almost makes up for it with some terrific sight gags: A lasso silently yanks away one thug after another; a helmet drops from the sky, preceding its owner by several puzzling seconds. In moments like these, the film briefly revs into the red.

So what's missing? For starters, a better villain than the cardboard Agent Fitzgerald (Peter Sarsgaard, on screen for all of five minutes). There's also zero chemistry between Cruise and Diaz, mostly because their roles are so generically written. What's more, while Miller turns out to be named Knight, there is nobody in this film named Day. It's one of many lost parts sitting somewhere back down the road.