A young man wakes up in a dreamlike landscape where he has strange powers but no memory. Is he a superhero? A cyborg? The resident of a virtual reality? The last man on earth? Alas, the answers will come as no surprise to anyone who's seen The Matrix. Funny thing is, Nick Sagan clearly has. The son of astronomer Carl Sagan has written scripts for Star Trek: Voyager -- and his influences show. (He calls his narrator Hal, a la 2001: A Space Odyssey, and makes the protagonist's parents ''celebrity scientists'' with their own TV show.) While Idlewild's bombshells fizzle, Sagan provides plenty of suspense and perfectly captures the angry adolescent solipsism that makes kids into hackers and superheroes in the first place.