Four girls at Scotford School became suddenly affected by strange black marks which appeared on their wrists. At the same time, they developed superhuman strength and an ability to run at great speed. Professor Burton, investigating the mystery, traced the girls to a lonely house in grounds guarded by a special fence and wild cheetahs. Carrie Norton volunteered to go in and investigate the house, where she discovered that the girls were being controlled by a man whose face she glimpsed on a close-circuit television network.
- The Black Marks – Judy: (?) – #525 (31 January 1970)