Dan Carter, his wife Sara and their two children are at Gatwick, about to get on a plane that will take them on their first holiday as a family. Sara has planned the trip in meticulous detail, but at the check-in desk, Dan finds his passport is missing. Exasperated, he tells them to go ahead. He'll catch them up. A few hours later, Dan sees on a newsflash that the plane has gone down over the ocean, and with a single blow his life is shattered. But after the first explosion of grief, the questions start to haunt him. Was it an accident his passport disappeared? Did Sara have an agenda - perhaps even a whole life - he was unaware of? Was he the intended target of a terrorist attack connected to his time as a sniper in Afghanistan or his spell in the security services? And if so, will they try again? Suddenly, it's like old times: alone, with danger on all sides, and instinct and training the only things he can trust. And as the search for answers sets him on a deadly trail of revenge, Dan realises that the truth may be the last thing he wants to find.