I recently read a biography of John McKinney, Medal of Honor recipient.  Interspersed every 2-3 chapters was a separate story line regarding the last minute shipment by U-boat of Germany's nuclear materials.  The boat set sail just weeks before VE Day and surrendered near the Cape of Good Hope when they received word of Germany's capitulation.

Mr. McKinney had an interesting childhood and the story of his heroism in winning the MoH is riveting.  Everything in between is more or less chicken soup.  He grew up. He got drafted.  He went to basic. He was sent here, there, and yonder.  I assume that the only reason that the author included the U-boat story was that he knew of it and needed filler to sell a full length book.

His narrative was that both the Germans and the Japanese had nuclear programs.  The Germans had the materials but not the theory, while the Japanese had the proper working theory on how to create a functioning nuclear device but did not have the fissionable materials.  Ergo they would have been able to build at least one useful device before the US could make its own nuclear strike.

http://uboat.net/maps/ - http://uboat.net/maps/