An imaginary friend is forced to consider retirement when his creator/best friend starts to grow up.

A family reunion goes awry when the oldest son makes the accusation that his dying father, a famed psychiatrist who also did work for the CIA, adopted his children for the purposes of psychological experimentation.

The teenager and skateboarder Alex is interviewed by Detective Richard Lu that is investigating the death of a security guard in the rail yards severed by a train who was apparently hit by a skate board. While dealing with the separation process of his parents and the sexual heat of his virgin girlfriend Jennifer, Alex writes his last experiences in Paranoid Park with his new acquaintances and how the guard was killed, trying to relieve his feeling of guilty from his conscience.