The rule against fighting on holy ground has been occasionally been indicated to be more than a rule of conduct to ensure there is an agreement of neutral territory and sanctuary. In the film , two immortals are dueling near a Buddhist shrine when one of their swords explodes and as wind suddenly rises around them. Sensing power, they stop their fight. In the TV series episode Little Tin God, the character Joe Dawson describes a legend that says the eruption of Mount Vesuvius was caused by two Immortals going at it in a Temple of Apollo in Pompeii, breaking the rule. However, he admits this is only a rumor with no evidence to back it up.