Part 1

In the Roman port of Osia Flavia Gemina meets her Jewish next door neighbour Jonathan while escaping a slave-trader in the graveyard.

Later, she buys a beautiful African slave-girl named Nubia. Flavia's father takes them all south to stay with Flavia's Uncle Gaius near Pompeii.

On the voyage, they find a mute stowaway named Lupus and save the famous Admiral Pliny from drowning.

Part 2

Soon after the new friends arrive in Pompeii, water boils, tremors are felt and strange portents occur, especially during the feast of Vulcan.

Studying the clues, Flavia realises Vesuvius is about to erupt and decides to warn Admiral Pliny.

As the mountain begins to erupt, Pliny launches his fleet to rescue the people living at the foot of the volcano, but will they be in time?