Morton Sinclair is a studious young man, whose main interest lies in philosophical studies. So he is surprised when Lady Isabel Forrester invites him to attend a Christmas party at Moorcroft Manor, an old country house in Yorkshire, which her friend Silas Overington has recently taken on. But Sinclair finds he has plenty of use for his intellectual faculties when Overington is found murdered in his study on Christmas Eve. Who could possibly have wanted Overington dead? And how is the tragedy linked to the legend of the cavalier, whose ghost is said to haunt the Manor?

Originally published in 1935, this is a vintage murder mystery from the golden age of British crime fiction.