The Swat Kats stop the Metallikats from robbing the Megakat City Mint, and in the process the two robot gangsters are severely injured, Molly moreso than Mac. When Mac finds out about Dr. Lieter Greenbox's new invention, the Micro-Brain Repair Unit which can fix anything, he immediately takes himself and Molly to Greenbox's lab and steals the device. The Metallikats use it to repair themselves, but in the process the device becomes contaminated by their criminal programming. Achieving sentience, it names itself Zed and proceeds to go on a citywide rampage, assimilating all manner of metal and machinery (including Mac!) onto itself, constructing an ever-growing armored shell. Naturally, only the Swat Kats can stop Zed, with some help from a vengeful Molly. Unfortunately, Zed's next stop is Puma-Dyne, where it plans to get its hands on the Mega-Beam laser weapon. Worse, Greenbox has become so impressed by what his genius has wrought that he's gone completely looney-tunes and is doing eve