When done well, they are scintillating cinematic brain teasers, and Timecrimes is one of the best time travel films to come along in, er, quite some time.

Yet while it isn't that hard to stay a step or two ahead of Timecrimes, the movie is still a nifty little genre piece, an old-fashioned science-fiction mind-game with a healthy dollop of "Oh, the irony."

According to rumors swirling on the Internet, an English-language remake is already in the works, possibly directed by David Cronenberg.

Vigalondo explores it (time travel) just enough to keep this thriller moving, and Karra Elejalde is entirely convincing as the unwilling time traveler, who finds himself threatened by not only his past self but his future one as well.

As a whole, the picture is, frustratingly, always much more about structure than substance.