In the city of Brudill, shapeshifting entities known as the Gunk invade causing destruction and misfortune to the citizens. To counter the Gunk, the Gunk Annihilation Service or GAS was formed. GAS now vows to protect Brudill by using the Gunk against itself with their Agent, Miles Mercer fusing with one codenamed, En to become GAS's ultimate weapon, "The Ripper".