A psychiatrist (Ewan McGregor) tries to help a patient (Ryan Gosling) intent on committing suicide in four days. But while struggling to deter the young man, the doctor’s own grip on reality seems to slip away—even his girlfriend (Naomi Watts) calls him by the patient’s name and then denies it. What’s going on? You may think you’ve got David Benioff’s script all figured out, with its broad hints about this and that—mistaken identity, miracle healings and other things—but believe me, you don’t. Under Marc Forster’s direction, you float weightless and unmoored in a nightmare, by turns riveting and exasperating, with dazzling hallucinatory touches in Roberto Schaefer’s cinematography. The last scene makes the movie and gives a glimpse of oblivion that isn’t easy to shake as you leave the theater.