Some authors just write about it. Chris Ryan has been there, done it, and lived to tell the tale. Agent 21 is the first in the action-packed adventure series by the real-life SAS hero.When Zak Darke''s parents die in an unexplained mass murder he''s left alone in the world. That is until he''s sought out by a mysterious man: ''I work for a government agency,'' the man tells him. ''You don''t need to know which one. Not yet. All you need to know is that we''ve had our eye on you. There''s a possibility you could help us in certain . . . operational situations.''Zak becomes Agent 21. What happened to the 20 agents before him he''ll never know. What he does know is that his life is about to change for ever . . .