Scientists will discover a way to bend the laws of time before anyone remembers that a movie about bending the laws of time has to have some way of handling the problem of determinism versus free will that is if not plausible then at least consistent.

The idea (from Blade Runner’s Philip K. Dick) is an intriguing one — a super-smart computer whiz who trades not only his intellect but his memory for big bucks.

Ben Affleck plays Michael Jennings, a brilliant engineer. In two months, he takes apart a revolutionary project for its competitor and makes it all but obsolete. Then the client writes him a big check, his friend Shorty (Paul Giamatti) zaps out his memory of the last eight weeks, and Michael is off to make the kind of memories he likes to keep, all of which seems fine to him. When Shorty tells him to think about stopping, Michael says, “My memories are basically highlights. The stuff you erase doesn’t matter.”

This of course is the set-up for that great movie plot device, the one last big job that is going to give Michael walk-away money for life.

Cue evil mogul Rethrick (Aaron Eckhart), who offers Michael a three year project. Then cut to three years later. Michael’s memory is gone, and so is the $90 million he was supposed to be paid. All he has is a manila envelope with a bunch of mundane items — hairspray, a fortune from a fortune cookie, a pack of cigarettes, a paperclip, a matchbook. He knows it was a message he sent to himself before his memory was wiped. But what does it mean? And will he ever remember his relationship with a beautiful biologist (Uma Thurman)?

Even on one of his good days, this set-up would have been a challenge for director John Woo, whose stylish staging has turned less-than-impressive scripts into highly watchable films. But Woo seems to have taken a hit from that memory-eraser. We can stand it when a thriller requires some suspension of disbelief (see Woo’s entertainingly preposterous Face-Off). But the one thing we cannot forgive in a would-be thriller is boredom, and this movie just sags, even in the action scenes. Without spoiling what little suspense there is, all I can say is that the big “reveal” removes any sense of narrative tension by making the outcome all but inevitable. Even Woo’s trademarks, the fluttering birds and the two-gun stand-off, feel perfunctory.

Parents should know that the movie has extended action violence with guns, chases, kickboxing, explosions, and character deaths. Characters use strong language, smoke, and drink, and there are mild sexual situations.

Families who see this movie should talk about whether there are memories they would like to or be willing to erase. If you, like Michael, wanted to make sure that someone really knew you, what question would you ask?

Families who enjoy this movie will also enjoy the superior Terminator 2: Judgment Day (also featuring Joe Morton) and Minority Report, with similar themes. And they might enjoy director John Woo’s better films, including Face-Off.