Rainbow six
Tom Clancy
At the heart of this novel is John Clark, the ex-Navy SEAL, or otherwise
known as "the dark side of Jack Ryan," the man who conducts the
secret operational missions in which Ryan can have no part. Clark is
efficient and deadly but he also has demons in his past that must be
exorcized and nothing is more demonic than the peril he must face in
"Rainbow Six," a group of terrorists like none the world has
ever seen.
This summary is courtesy of McNaughton Books.