On behalf of British Intelligence the Saint journeys to Hamburg to locate Professor Roeding, who disappeared whilst shopping for antiques there and after ringing his daughter to say that he was on the verge of making a fortune. Re-tracing the professor's steps the Saint is approached by Eva, a young lady who takes him for a night on the town and then spots a goblet in the window of a pawn-shop. She claims it is an antique and buys it. Breaking it into pieces she finds a message, allegedly written by a fifteenth century pirate, revealing the location of his treasure. But the Saint is aware that it is quite plainly a scam, and, in all probability, the same one that caused Professor Roeding to fall into the wrong hands. Thanks to this information he is now in a position to rescue the gentlema