When words of new superhero team appeared in the city of Broncotopia, both Zapp and Mistress Mare-Velous were sent to city to try and talk to the heroes into becoming the members of larger organization of heroes. Unbeknownst to them the two stumbled onto a plot by an pony who is planning to eliminate all criminals in ths city, permanently. Now it is up to the two Power Ponies and these other heroes to combine forces and take down this mad pony.