It's another peaceful day in the land of Valley—until Pondside receives a dark and unexpected visitation.

While Helga tries to warn everyone of the coming danger, Goodhill throws Mabel a birthday party.

Mabel and her friends investigate the ruins of Pondside, and find a new ally—along with a few new enemies.

Mabel's band of heroes learns the cause of Maha's rampage, and Ral learns he isn't the only visitor lingering in Bloomburrow.

As heroes, villains, and monsters make for Fountainport, Helga returns to her old master.