A chaotic duel with characters from The Epic Tales of Captain Underpants and PJ Masks erupts when George, Harold, Mr. Krupp and Erica got send to a other dimension which just happens to be in Tarabiscoville, The PJ Mask’s HQ, but Catboy, Owlette and Gekko accidentally teleports themselves into George and Harold’s dimension.
Now the heroes are stranded in each other's worlds. Now George and Harold must shut down PJ Robot, who George uploaded a destructive video game into, before he destroys Tarabiscoville. Meanwhile, The PJ Masks must stop Melvin Sneedly from taking over Piqua.
