Dillwyn is planning to return to Wales to spend Christmas with her dear friend Gengi. As she looks out the window at the snow, her mind is on other things – mainly Monk and the journals they found in the trunk from the Crystal Cave.
Suddenly, Dillwyn is transported back in time to the eruption of Mount Vesuvius in 79 A.D.
How did she get there?
What adventures are in store for her?
What terrors await her?
How will she get home – or will she?