In Dartmoor, a punk band get into a fight with a group of rich and rowdy young students, whose Range Rover crashes into their car. The group's are spurred on to insane acts of violence by a mysterious force, and the punk band singer hears a voice in his head which directs him towards a rusty knife buried in the ground. Murder ensues and blood soaks into the rock.It is much later on that a creature emerges from the bloody rock, greedily anticipating the chaos that it plans to cause...The TARDIS alerts the Doctor to an incongruous energy fluctuation in the south-west of England. There he finds himself part of the audience at one of the band's gigs, and their anarchic music is attracting an ever-growing convoy of violent disciples.