A wonderful, off-beat surprise. THE ZERO EFFECT takes one by surprise about a third of the way through -- it actually has a story and believable, original characters to guide us through its enjoyably labyrinth plot. Debuting writer-director Jake Kasdan (son of Lawrence, who gave us THE BIG CHILL) shows an uncommon talent for vivifying characters without overscaling them, for using the camera very subjectively yet unobtrusively, and for modulating performances that results in career-best work from Bill Pullman and Ben Stiller. Pullman, in particular, is quite outstanding, making his wacky, intelligent character thoroughly believable and irresistably ingratiating. This one's a real prize.