When Sarah Jane disturbs a burglar in the night, she is surprised to find a middle-aged woman, her pockets stuffed with jewellery, demanding gold. The next day, she reads a newspaper story about a granny who broke into a jewellers, and then Maria reports that a woman has been stealing rings and necklaces from the girls' changing room at school. All the women had recently attended the Auriga Clinic, a private health centre specialising in treating muscular aches and pains. Is there a link between the clinic and the odd behaviour of its patients?