"Every Thursday, three retired school teachers have their 'coffee o'clock' sessions at the Thirsk Garden Centre cafe. But one fateful week, as they are catching up with a slice of cake, they bump into their ex-colleague, Topsy. By the next Thursday, Topsy's dead. The last thing Liz, Thelma and Pat imagined was that they would become involved in a murder. But they know there's more to Topsy's death than meets the eye - and it's down to them to prove...