The Bay of Saint Michel

Three ex-commandos on the reserve list recalled for Operation Mermaid under the command of their wartime C.O., Rawlings, receive their operational orders off the coast of France. They are to recover the two missing parts of a chart locating Nazi loot hidden by a German general at the end of the war in collaboration with a French and an American officer. In Cherbourg they meet Helene Bretton, who knows the whereabouts of the Frenchman. He is dead but a painting of his which they buy contains his part of the chart and Helene has the third. They discover the hiding place on Mont St. Michel. Helene then reveals that Rawlings was one of the original owners of the chart. He plans to seal them in the vault but NATO, already alerted by Helene by radio, arrive with gendarmes and Rawlings, escaping, is caught in the quicksand.