Twins Poppy and Bergie share everything, including an ability to read the mysterious book that Bergie gets Mardi Gras Day when the Muddy Graws debut in the Rex parade. Two potential Keepers makes double the work for the Custos guardian, who can't be two places at once. Poppy's book grab from its hiding place in a fit of anger potentially changes everything, and could shift the balance between light and dark. Sebastian Winder has his hands full. The new Keeper has a twin who knows more than she should, and who is actively interacting with a member of White Diamond. 1920 can't come fast enough. Fearing the inevitable worst, the guardian asks for an assistant. Who he gets, is Ramsby Roth, a fresh from the Farther Fields, greener than green Custos with no experience. In this third installment, it might take every one available to keep the book from the wrong hands as the odds are stacking against them. Just when they think the end is in sight, World War I erupts, Bergie is sent to serve, and Carnival festivities in New Orleans are cancelled. What if there's no Mardi Gras? How can they keep the book safe now, or get it to the new Keeper? Only the book knows.