This was a combination of spy story, international intrigue, nuclear weaponry, Middle East conflicts, banking secrecy and also hard to believe----but, well, possible.
Main character is a physician serving with Doctors Without Borders on a ski trip with his wife in the Swiss Alps. She slips into a crevasse and dies. Then a package arrives addressed to her which he retrieves. As he tries to find the answer to its contents he finds himself being chased by police and top government officials. His wiff becomes a mystery person involved in activities that he can't discern.
We go back and forth in the story learning how it all fits together.