Sidney Sheldon 
Doomsday Conspiracy [EPUB ebook] 

OPERATION DOOMSDAY… ACTIVATE…Commander Robert Bellamy of US Naval Intelligence is dispatched on a top secret mission. A weather balloon carrying sensitive military information has crashed in Switzerland. Bellamy must locate the ten witnesses to the incident so that they can be sworn to secrecy.But as he conducts his search Bellamy begins to suspect that he, too, is being hunted, by an unknown lethal force… that what he was told about the balloon was only one part of an almost unbelievable happening..