THE TIDE AT HARROWGATE

December 1936. A storm. A tidal island. A house full of people with something to hide.
On his seventieth birthday, shipping magnate Sir Lucian Harrowgate gathers his family at Harrowgate Manor. At dinner he announces that one of them has been stealing from him, and that at midnight he will name the thief.
He never gets the chance. Sir Lucian is found dead in a locked study, and the rising tide has cut the island off from the mainland. The telephone is dead, and no police can arrive before morning.
Ambrose Pellew, a retired codebreaker with a passion for old clocks, had been quietly asked to attend. He now has one night, seven suspects and a stopped clock on the landing. As a second death follows, he must find out who among them is willing to kill twice.