From The Shadows : Alex King Book 8(Alex King‪)‬

The agents from an MI5 mission against the CIA are being hunted and killed. With his team dispersed in anticipation of fallout from the operation, King must bring them back together and meet the threat head on. But this is not an official CIA mission, and the driving force behind these acts of vengeance could soon be the most powerful man on the planet.
“Alex King is unstoppable, a force to be reckoned with…” – STEPHEN LEATHER