Andrew Ryan always dreamed of being like his superhero idol, Defender, so he could stand up to bullies and his big brother. His dream comes true when an explosion kills Defender and transfers Defender's superpowers to Andrew. Donning a homemade costume to hide his identity, Andrew soon earns the name Smash defending Seatown from evil, but battling villains, particularly the Magus, who wants to steal Smash's powers, may prove to be more than a nine-year-old can handle.