In countess Potrulla’s possession is „Hell Fire“, one of the most magnificent rubies known to man. However, the precious stone means almost nothing to her. She would much more enjoy enslaving the ornamental tick Nihilit. The reason is simple: When Nihilt swells up to the size of a hen’s egg, it sends out a sparkling red light that can illuminate the darkest room. Finally, Potrulla puts out a reward: Whoever catches the elusive parasite will receive silver to the amount of twelve times his own weight.

Nihilit knows about the chase. To be prepared for the worst case, the tick is sticking to its daily exercises on the keep-fit trail atop Thor’s Oak. Until that fateful day when a wild boar rubs against the tree …