Once a week, three retired school teachers have their 'coffee o'clock' sessions at the Thirsk Garden Centre cafe. But one fateful Thursday morning, they bump into their ex-colleague, Topsy, during their weekly coffee and catch-up. By the next Thursday, Topsy's dead. The last thing Liz, Thelma and Pat imagined was that they would become embroiled 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 it.