Can Thelma and Digby stem the tide of the super rats? And what sort of rat wears a green ballet dress or is called Kes?

Rid-O-Rat is about to launch a sensational new pesticide. Thanks to Digby, the secret formula suddenly vanishes. Thelma turns safebreaker extraordinaire to save the situation.

Thelma has a long-established domestic routine for running Mr Digby's office, but Digby's home has quite a different atmosphere...