During a mission to retrieve information in Robotropolis, Sally Acorn jumped on top of the locomotive and climbed inside with Nicole in hand. She quickly discovered the DYNAMAC and Geoffrey St. John quickly discovered her. Soon, Geoffrey's men, Dolph and Jean-Claude, attempted to stop the engine of the Robotnik Express and accidentally activated a fail-safe and the DYNAMAC in the process. The DYNAMAC then went up against Sonic, Geoffrey, Sally on the still moving train and Rotor and Antoine on their plane. Sonic then managed to disable the DYNAMAC's systems using a gadget supplied to him by Rotor and Dolph then fired on the DYNAMAC after Jean-Claude saw Geoffrey's signal, completely destroying the robot. The Knothole Freedom Fighters and Geoffrey's men then decided to make use of the train