When Billy, Mandy, Grim's Scythe, and Nergal Jr. get sucked into a vortex and is captured by Quintessons and the Boogey Man. It's up to Starscream, Grim, and Nergal to save them and Earth.

First real episode of the series. Starscream is learning to cope with his new way of life with Billy, Mandy, and Grim. But what happends when Billy needs someone for a science project and wants to use Advenced Cybertronian Tech and Underworld powers?

Megatron and Mandy make at bet for their friends. If Mandy wins she gets Starscream and if Megatron wins he gets Grim. Who will win? A Transformers and The Grim Adventures of Billy and Mandy Crossover.