Thirteen-year-old Guy Martin, also known as superhero Pumpkin Pete's sidekick Speedy, helps the League of Big Justice save the human race from being turned into puppets by Pinoh Keyoh and the Brotherhood of Rottenness.

Speedy and the other sidekicks help out when the League of Big Justice faces its stickiest, most chocolatey supervillain yet--the Candy Man, who is determined to rot the world's teeth one cavity at a time.

After Pumpkin Pete accidentally blows up the League of Big Justice and the Sidekick Super Clubhouse, the superhero trouble begins.