International bestseller: First in the gripping military action series by the special forces veteran and star of SAS: Who Dares Wins. A country in turmoil. A rescue mission gone wrong. A hero on unlike any other fighting to save a broken world . . . Matt 'Mace' Mason is deployed on a deniable SAS mission in war-torn Yemen when he becomes embroiled in a hostage rescue that goes terribly wrong. Pulling at the strings of the local political scene is not only the warlord destined to become Mace's nemesis, Gen. Ruak Shahlai, but hard-bitten American arms dealer Erica Atkins, who controls a whole international network to her advantage. Mace has to work, unwillingly at first, with female CIA agent and Islamic scholar Redford. Together they must prevent an attack that would spark a regional war and create the largest environmental disaster the world has ever seen. From a seventeen-year SAS veteran who operated in Iraq, Afghanistan, and other global hotspots, served as a bodyguard to major celebrities, and appears on the British series SAS: Who Dares Wins, "this special forces thriller is bang on target" (The Sun). "From the dramatic opening sequence to the powerful, emotional ending, Billy Billingham's debut, Call to Kill, never fails to deliver. . . . Captivating insight into the clandestine world of secret operations [and] a wonderfully engaging protagonist." --Adam Hamdy, The Sunday Times-bestselling author of Black 13