"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 cloud of fiery ash and rocks fall from the sky like rain, will they have time to...

Their magic tree house takes Annie and Jack to Pompeii just as Vesuvius is about to erupt, and they must find a Roman scroll before everything is covered with burning ash.