With barely a moment's distinction between reality and dreams, Alejandro Amenábar's maddening existential thriller Open Your Eyes persistently undermines conventional notions of time, setting, and personal identity. To what end remains similarly ambiguous, but as an especially severe case of millennial anxiety, the film is nonetheless an intriguing (if unsolvable) puzzle. Lifting elements from Blowup, Vertigo, Seconds, and the paranoid universe of Philip K. Dick, Amenábar and co-writer Mateo Gil open the story at a psychiatric hospital where wealthy playboy Eduardo Noriega is being held for murder and flashes back from there. Of course, the psychiatric hospital may or may not exist, the murder may or may not have occurred, and the flashbacks don't always lead to reliable places. A profoundly superficial man, Noriega has his face disfigured during a suicidal car accident staged by jealous ex-girlfriend Najwa Nimri after she catches him with a shallow actress (Penélope Cruz). But even that event is called into question when Nimri unexpectedly reappears and assumes the other woman's identity. Given that the only character who certainly exists is a blank slate of the David Hemmings variety, Open Your Eyes works strictly as a cinematic exercise. But at 25, Amenábar already displays an impressive command over the medium, and once the internal logic of his story takes hold, its subtle intricacies are enough to sustain it.