Three wealthy children's parents are killed in a fire. When they are sent to a distant relative, they find out that he is plotting to kill them and seize their fortune.
There's trouble brewing in Bikini Bottom. Someone has stolen King Neptune's crown, and it looks like Mr. Krab, SpongeBob's boss, is the culprit. Though he's just been passed over for the promotion of his dreams, SpongeBob stands by his boss, and along with his best pal Patrick, sets out on a treacherous mission to Shell City to reclaim the crown and save Mr. Krab's life.
When Earth astronaut Capt. Chuck Baker arrives on Planet 51 -- a world reminiscent of American suburbia circa 1950 -- he tries to avoid capture, recover his spaceship and make it home safely, all with the help of an empathetic little green being.
