Knuckle

Curley Delafield, a young arms merchant, determines to discover the secret behind the disappearance of his sister Sarah, whom he has not seen for a dozen years.  Sarah had disappeared from the deserted stretch of beach between Pevensey and Eastbourne known as the crumbles, a scene during the 1920's of the notorious Patrick Mahon murder - which casts a shadow, perhaps deliberately, over the whole mystery.  Also involved is the Shadow of the Moon Club in Guildford, together with Henry Wilbur, in whose flat Sarah lived at one time, before running away to - all all places - Surbiton.  Curly's investigations lead him to uncover corruption and rottenness under the placid surface of Guildford where his father, a city man, lives in circumstances of some intimacy with his housekeeper, Mrs. Dunning.