When businessman Marshall Allerdyke receives a late night message to meet his cousin in Hull, he makes a late night drive only to find on his arrival that his cousin is dead. Further investigation reveals that he had been carrying a fortune in jewels that has now gone missing. Allerdyke vows to track down the murders at any cost. But to do so he must discover whether the mysterious woman he had met traveling to Hull was the one who left the jeweled buckle in his cousin's room, and if he can trust his cousin's American business associate Franklin Fullaway. But most important of all, he must determine what role was played by The Rayner-Slade Amalgamation