The Doomsday Conspiracy by Sidney Sheldon
Book Description :-
The Doomsday Conspiracy is a thriller novel by American writer Sidney Sheldon published in 1991 .The protagonist of the story is Robert Bellamy, a man hired by the NSA to locate the several bus passengers in Switzerland who had accidentally saw a weather balloon with some top secret equipment (later on identified as a UFO) collapsing in the woods. As Robert locates the passengers one by one, they are mysteriously killed. Each murder has been meticulously staged to appear as an accident. Robert's marriage also dissolves, as his wife, starved for attention by Robert, marries a rich business tycoon.