Kirsty, a cashier in a toy shop, arrives at work to find the Doctor and Romana outside. The Doctor asks if she's seen anything out of the ordinary, and she admits that she hasn't. Kirsty later eavesdrops on the pair, who are conversing with a doll. She admits that she's heard strange noises and seen things out of the corner of her eye. The Doctor assures her that things will be quieter from now on.
The Doctor and Romana apprehend a teddy bear and two dolls who are stealing candy from a sweet shop. The toys are being controlled by children from the planet Elden Twelve. The Doctor threatens to tell their parents, and they promise not to do it again.
A week later, the Doctor and Romana return to the toy shop, now quiet. Kirsty gives the Doctor a yo-yo as thanks for his help.
- Kirsty gives the Doctor a yo-yo.
- The toys eat peppermints and chocolate.
- Kirsty is a university student.
- The title may be in reference to the 1988 American horror film Child's Play, which also featured dolls coming to life.