As a human, Nerville feels he's missing out on the fun - so he enlists the aid of the sinister Broccoli Alien Overlord to become one of the fruits.
Nerville is hurt that he's excluded from a fun fruity party. So he happily takes the sinister Broccoli Alien Overlord up on their offer to let him see life from the produce point of view. That entails leaving his human body in their cruciferous care - what could go wrong?—Annoying Orange