Charles Mortimer has passed down to his descendants, the Collards and the Vandervents, vast wealth, prestige, a successful business and a horrible string of bad luck that began when he built the two eccentric mansions on the fringes of Blackheath. Roger Vandervent, the prosperous manager of the family company, is mysteriously struck down with food poisoning and dies. Only his son Paul suspects murder, and the subsequent disappearance of secret letters written to Roger only confirms his suspicions.

In attempting move attention away from his adored Aunt to Isabel, whose relationship with his father was little short of scandalous, Paul plunges into a nightmare of blackmail, adultery, and secret sexual aberrations.