Thrash rock group (it stands for Mad Cow Disease) descend on Mount Thomas and every kid in town seems to be mad about them. They heavily promote violent images but it's the throwing of containers of blood over their fans that brings them into the station after their first gig.
The fan was actually flattered to have been chosen, so the band get off with a warning but Tom is worried by their presence. His fears appear to be confirmed when he discovers one of the station's vehicles defaced with images resonant of MCD.
But that is only the beginning of the Heelers problems with the band. A vandalised angel in the cemetery relates to the band's signature song "Bloodstained Angels" and then a blazing car in the car park of the Commercial Hotel conjures up another line of lyrics from the same song.
Meanwhile, a father seeks the help of the police in rescuing his son from the spell of the "demonic band". Tom is sympathetic, but there is only so much the local police sergeant can do, despite the gallery of death and destruction on the boy's bedroom walls.
By now the peace of Mount Thomas appears to be shattering and the Heelers must determine whether they are looking for a publicity stunt, an avenging father or an adoring fan. As they look more closely at the lyrics, they realise that they have to act quickly because a direct attack on the police is next on the agenda.
