The Knights of Atlantis / Andy McDermott.

Archaeologist Nina Wilde and her husband, former SAS soldier Eddie Chase, believe their globe-trotting adventures are over, the biggest worry being how their now-adult daughter Macy is going to spend her life. But after the violent theft of dangerous relics, with the only surviving guard claiming his attackers were "angels", Nina and Eddie are thrust back into action. Without their knowledge, though, Macy is approached by a mysterious group called the Knights of Atlantis, who want to recruit her. In a deadly race stretching from the glamorous French Riviera to the blistering heat of the Karakum desert, Nina and Eddie must confront mercenaries, secret societies and the machinations of the world's first trillionaire, with the fate of the world in their hands.