In this second instalment of the Invisible Library series, Librarian Irene is installed in a Victorian London with her apprentice Kai. When Kai is kidnapped, Irene has to travel to Venice in a Fae-dominated world, where it's permanently Carnival. Irene must rescue Kai to prevent a war, but doing so will violate the Library rules. The result is a slightly chaotic romp through Venice, as Irene seeks to outwit the kidnappers and the many obstacles they place in her path. We learn more about the nature of the Fae and of the Dragons, but as Irene is acting outside of her role as a Librarian, this episode is far less focused on books.