Earth (Billy Gets an "A" Universe)

There was a test in the school of Billy.He gets an F so he requested Grim to  turn his F grade into an A. At last Grim turned the F grade to an A. When he does that all the things appeared strange like Harold was doing the chores of house dressed as Gladys and she was dressed like Harold and was gone office and many things like this. When Grim was irritated from it, he and Mandy decided to go back in time to stop Billy.But they were failed everytime.