Thunder Point (Sean Dillon) by Jack Higgins

1945. The day before Hitler commits suicide, he arranges for Nazi leader Martin Bormann to flee to South America in a German U-boat.

1992. Terrorist Sean Dillon is saved from a Yugoslavian firing squad—if he agrees to help the British government retrieve the long-lost documents of Martin Bormann. The wreck of Bormann's U-boat has been discovered in the Caribbean, along with a secret list of Nazi sympathizers. The names include high-level citizens from the U.S. and Great Britain—and may implicate the Duke of Windsor himself. The evidence lies in a watertight briefcase on the bottom of the sea. And the desperate search to find it will send shockwaves across the world ...