The Fantastic Four drop Franklin off at the Power family's apartment. He will be staying with the Powers while his parents, Reed and Sue, are on a mission with the FF. The Power siblings are thrilled to have their friend and teammate staying with them for a while.
However, Master Mold is searching for Franklin. He has a mission to exterminate the boy because he is the Twelfth - the twelfth great mutant, whose power as an adult will be almost unlimited, who will have the ability to bring down the Sentinels. He tracks Frank to Central Park, where he is playing alongside the Power siblings.
In the ensuing battle, Master Mold manages to take down all four Power siblings. As he is about to crush them with his foot, Frank emerges from hiding and sacrifices himself to save his friends. As Master Mold prepares to crush him, Katie (Starstreak) revives and flies right under the robot's foot to save Franklin. The team revives and the battle continues.
Even when he is seemingly blasted to pieces, Master Mold regenerates himself and keeps going. Alex finally disintegrates as much of Master Mold as he can, becoming physically larger and suffering great pain as a result. He blasts the energy back at the robot and finally destroys him. Power Pack leaves the park, safe and sound.
However, in the very last panel, a beeping noise emits from the rubble of Master Mold's body, suggesting that he isn't really gone.