Some Authors Just Write About It. Chris Ryan Has Been There, Done It, And Lived To Tell The Tale. This Is The Second In The Action-Thriller Agent 21 Series By The Real-Life Sas Hero.In The Year Since Zak Darke Was Approached By A Shadowy Government Agency To Become Agent 21, His World Has Changed Completely. But There Is No Time To Reflect On This - The Undercover Operations Go On. Zak Is Sent To A Port In West Africa, A Known Terrorist Stronghold, Under The Guise Of Working Ona Charity Volunteer Project. , , But Charity Work Could Not Be Further From Zak's Real Mission - He Must Sneak Onboard An Enemy Ship, Gather Information - And Then Destroy It. Never Has Zak's Training Been More Useful: Trust Nobody.