Something is wrong in Hell.
A mysterious ritual gone awry has bound Satan to the soul of the very ordinary and very confused Mikaela, latching onto her on the day she was born. His powers greatly diminished and unable to return home, Satan and Mikaela settle into a cease-fire as they try to maintain the semblance of a "normal" life while investigating the magic spell that binds them together. After a chance encounter with a dark sorcerer...