In the novel Dead Man's Folly, Helmmouth is a town in Devon near Nasse House. It is situated, as the name suggests, at the mouth of the river Helm. Tour boats depart Helmmouth carrying sightseers pass Nasse House. Etienne de Sousa moored his yacht at Helmmouth and made his way to Nasse House with his launch.
Nasse House is based on Greenway, Agatha Christie's holiday home in Devon on the river Dart. Helmmouth corresponds to the town of Dartmouth.
Helmmouth Police Station[]
The police station at Helmmouth has jurisdiction over the Nasse House area. During the course of the events in the book, the following personnel from the station were involved in the investigations:
- Inspector Bland
- Sergeant Frank Cottrell
- Constable Bob Hoskins
- Alice Jones
- Constable Lorimer
- Sergeant Farrell
- Superintendent Baldwin
Connected with the police at Helmmouth is Dr Cook, the police surgeon. The personnel there are supervised by the Chief Constable of the county, Major Merrall.