Professor von Volt plans to send Geronimo and his time traveling friends back to King Solomon's court to borrow a ring that supposedly will restore harmony to Mouse Island and balance the environment--but they soon find themselves taking an unplanned detour through Napoleon's court, a Viking village, and the Minotaur's labyrinth, before finally arriving before the wise King.

Translation of: Viaggio nel tempo-5. Geronimo Stilton is a book character who is the attributed author.