Books in the SIGMA FORCE series

A sinister fire in a Copenhagen bookshop ignites a relentless hunt across four continents...A superb SIGMA FORCE thriller from the bestselling author of MAP OF BONES and THE DOOMSDAY KEY.

Can the past save the future? asks the latest SIGMA Force thriller from the king of the genre.

An ancient menace reborn to plague the modern world...and an impossible hope hidden in an unimaginable place...The exhilarating SIGMA Force thriller from the NEW YORK TIMES bestselling author of MAP OF BONES and THE DOOMSDAY KEY.