Billy's dad has gotten a new job. Billy and his family are going to have to move to another part of town. However, he's always lived near to Mandy, and the two of them share the Grim Reaper. By Billy's relocating, this means that they have a problem. Who gets to "keep" Grim? Should Billy be the sole "owner" of Grim, and take him with him upon moving. Or should Grim be given to Mandy, and stay with her? To resolve this, both of them take their dispute to the Underworld Court, where a jury of hideous, nightmarish creatures (including one really annoying one) will decide once and for all who is truly the "Keeper of the Reaper."