The Sixteenth Stair

The Sixteenth Stair is a 1942 detective novel by E.C.R. Lorac, the pen name of the British writer Edith Caroline Rivett. It is the twenty second in her long-running series featuring Chief Inspector MacDonald of Scotland Yard, a Golden Age detective who relies on standard police procedure to solve his cases.

Synopsis
A nineteenth century villa in St John's Wood has been owned by the Hazely family since it was built, but it now lies abandoned and empty. When an American cousin pays an unexpected visit to the old house, he discovers a body lying at the foot of a staircase with its neck broken. As MacDonald investigates it soon transpires that the house has not been as abandoned as widely thought.