Dorkius is annoyed when he has to move with his family to Pompeii for the summer in his third adventureDorkius has to leave behind all the joys of Rome for a boring small town. He finds the people of Pompeii to be even more superstitious than his mom, and watches in disbelief as they base all their decisions around animal innards readings. Things brighten up when he meets Decima, a local girl who's convinced a demon is haunting nearby Mount Vesuvius. They go off to investigate and Dorkius finds that the demonic rumbles are coming from inside the volcano itself. Convinced that Vesuvius is about to erupt, Dorkius rushes down to the town to warn everyone, but will they listen?