Candace (the First Gladiator) and her adopted son Alan Harris are summoned by Candace's father, Aznavorian the Tinkerer (in his "Skeeta Jenkins" incarnation), when he discovers lost refugees from other worlds trapped in Gotham City of the Nolanverse. The refugees in question are Scooby-Doo and Mystery Inc., as well as a few characters from Sesame Street. Getting them back to their worlds should be easy, right? Well, there's the matter of two Sesame Street natives getting lost in Gotham, a determined yet dedicated police detective hot on their trail, and Candace experiencing her first-ever regeneration into Sonia, the Second Gladiator!