In one of their travels through time, the boys visited Pompeii as it was in 79 A.D. During that trip they met Tullius, a nine year old Roman boy who worked in his father's chariot repair shop. During an attempt to capture Erbert and Gerbert, Comet Morehouse flew too close to Mount Vesuvius and caused the volcano to erupt and totally destroy Pompeii. Luckily, Tullius and the boys were saved when Tullius outran the lava flow and ashes in a racing chariot that he found in the family shop.