Planet 51, the white picket-fence world reminiscent of 1950s America is happy, safe and predictable. until the unpredictable happens! Out of the blue, Captain Charles 'Chuck' Baker's spaceship comes crashing down. Unaware of his surroundings, Chuck begins to realize that he is not alone. Taking refuge while planning his return home, Chuck meets green-skinned local, Lem, and realizes that he may be the real 'alien' after all!