Connington switched to a new series character Superintendent Ross for his next two novels, before bringing back Sir Clinton in a fresh story The Boathouse Riddle in 1931.

[5] Returning from a visit abroad Sir Clinton, recently having resigned from his post as Chief Constable, goes to stay at his widowed sister's rented country estate at Raynham Parva near a small village of the same name.

Sir Clinton is called soon afterwards to give some assistance to Sergeant Ledbury of the local police on what looks like an accidental death in a car crash with the victim having gone headfirst through the windscreen.

When the doctor is found shot dead at a local megalithic structure, Sir Clinton is confirmed in his view that Francia is one of the smugglers, plotting to take the four young woman and sell them into White slavery across the Atlantic.

He is caught in a dilemma of whether to expose Francia in England or in South America, where it may cause less scandal for his niece's reputation, ot take more drastic steps.