Towards Zero

The book starts with a discussion of murder and how the murder is always the culmination of a series of events. Gull's Point is an idyllic country house owned by the elderly Lady Tresillian. An ill-assorted house party gathers at the house one September and there is a death which may or may not be suspicious and then a murder. The evidence seems to point to one person but it seems impossible that this person could have committed the crime.