Dan Shepherd is used to putting his life on the line. Working for an elite undercover squad, he’s lied, cheated, and conned in order to bring Britain’s most wanted criminals to justice. But when a powerful drug lord starts to kill off witnesses to his crimes, Shepherd has no choice but to go undercover in a high-security prison—a world where one wrong move will mean certain death. As Shepherd gambles everything to move in on his quarry, he soon realizes that the man he’s hunting is far more dangerous than the police realize—and that he’s capable of striking outside the prison walls and hitting Shepherd where it hurts most.