'Apparently the thigh bone had been bitten clean through - with one snap of the teeth.' 'There isn't a creature on Earth capable of doing that!' After a skirmish with an alien warrior in the Middle Ages, Sarah Jane Smith's life as a journalist in Croydon seems rather tame. She decides to track down the enigmatic character who took her back in time; with the Doctor, a good story is never far away. Her intuition pays off. The Doctor and UNIT are called to investigate a grisly murder at Space World, a futuristic new theme park. Tagging along, Sarah and her new colleague Jeremy soon find themselves facing huge crab-like creatures, mind-controlling devices and vicious flesh-eating beetles. And those are just the attractions...