On his return from South Africa, Charles Knox is invited to spend the weekend at the country home of Sir Neville Strickland, whose beautiful wife Rosamund was once Knox’s fiancée. But in the dead of night Sir Neville is murdered. Who did it? As suspicion falls on each of the house guests in turn, Knox finds himself faced with deception and betrayal on all sides, and only the enigmatic Angela Marchmont seems to offer a solution to the mystery.