Krang and Shredder decide to use Ireland as their base for the Technodrome. With a device called the Rainbow Trans-Charmer, the villains intend to turn harmless little creatures like sheep and rabbits into slavering beasts. The Turtles and Splinter, vacationing in Ireland, are attacked by the monster-sheep and track Shredder, Bebop and Rocksteady to the Dublin Zoo, where they are transforming the animals.

A descendant of the Viking raiders, Eric Red, seizes both April and Professor Swenson's map to the underground volcanos in Scandinavia. He plans to tap into the molten energy, melt the polar ice cap and flood the world's coastal cities, making them easy prey for his wanna-be Vikings.