The Rayner-Slade Amalgamation

A businessman learns that his cousin, who arrived by ship, has been found dead under suspicious circumstances; an initial medical verdict of heart failure is challenged by a doctor who suspects poisoning, and the disappearance of valuable jewels complicates matters. An American acquaintance joins the inquiry, and the investigation threads through boarding-houses, foggy streets, exotic connections to a foreign princess, and a circle of possible villains. Multiple murders, cryptic parcels, photographs, and financial clues are pursued by family and detectives until accumulated evidence and explanations reveal how theft, deception, and murder were orchestrated.