Freelance journalist Lindsay Gordon is strapped for cash - otherwise she would never have agreed to cover a fundraising gala at Derbyshire House Girls' School. But when the star attraction is found garrotted with her own cello string, Lindsay finds herself investigating a vicious murder. Who had the key to the locked room in which the body was found? And who could have slipped out of the half at just the right time to commit this calculated and cold-blooding crime?