From the bestselling author of the Event Horizon Series. It's been a year since Colton's wife died and he's unable to move on. He thought that a weekend to Yellowstone would help. Maybe he could reconnect with his son. But, just as they arrive, the supervolcano comes to life. Now, Colton and his son are thrust into a desperate struggle to survive, while outside the park, society is pushed toward the brink of collapse.