The Gadget clan faces one last threat from M.A.D.'s Dr. Dumbkopf, which involves battling his hulking, irascible humanoid assistant named the Grappler. 

Under the guise of a local telephone company, M.A.D. inventor Dr. Spectrum and his goons systemically target the mansions of Metro City's elite neighborhoods and proceed to burglarize them with the dial of a number and with a zap of a teleportation gun to send the loot straight into Claw's hands.