From A. G. Riddle, the Amazon and Wall Street Journal bestselling author with nearly five million copies sold worldwide in twenty languages, comes an epic standalone adventure with a surprise ending unlike anything you've ever read before. After a mysterious global event known only as 'The Change', six strangers wake up in an underground research facility where they learn that they're part of the Extinction Trials - a scientific experiment to restart the human race. But the Extinction Trials harbours a very big secret.