When the aqueduct that brings fresh water to thousands of people around the bay of Naples fails, Roman engineer Marius Primus heads to the slopes of Mount Vesuvius to investigate, only to come face to face with an impending catastrophe.

"No one in the bustling city of Pompeii worries when the ground trembles beneath their feet. The beast under the mountain Vesuvius, high above the city, wakes up angry sometimes--and always goes back to sleep. But Marcus is afraid. He knows something is terribly wrong--and his father, who trusts science more than mythical beasts, agrees. When Vesuvius explodes into a huge cloud of ash and rocks that fall from the sky like rain, will they have time...