The Monkees

Peter browses through a pawnshop owned by a mysterious man known as S. Zero. He meets Zero and the two chat about the varied instruments he sells, Zero talking cryptically about the instruments' previous owners. Peter notices a harp and falls in love with it although he has never played one before. When he says he would give anything for the harp, Zero makes a deal: Peter will sign a contract to own the harp and pay for it later. Peter happily signs, carries the harp home, and does not see when Zero makes a phone call to inform his home office that he--in reality, The Prince Of Darkness--has purchased Peter's soul. Zero later appears at The Monkees' beach house and tells Peter he can play the harp; when the initially-disbelieving Peter begins playing and finds he has great dexterity in doing so, Zero disappears and Micky, Mike, and Davy are left surprised at Peter's ability. The Monkees integrate the harp into their touring act and are an enormous success--until Zero returns and it is revealed that he is The Devil, who now wants Peter's soul by midnight, although Mike vows to take Zero to court over his contract, leading to a trial in Hades itself at which Peter must prove to a waiting gaggle of criminals that he can play the harp on his own, without Zero's help.

The Monkees are lured to the lab of a mad scientist, only to have their musical abilities, put into a Frankenstein-like monster.