Abigail hopes that her birthday will slip by unnoticed and uncelebrated, but her employer, detective of the supernatural R. F. Jackaby, has other plans. Using magical party crackers that teleport the pair to unknown destinations in time and space and a cryptic map that may lead to a forgotten treasure, Jackaby intends to give Abigail what he considers to be the best gift of all--adventure. Abigail and Jackaby must tame an enormous (and carnivorous) rabbit, defend a castle, and master a dirigible if they want to find the treasure and get back to New Fiddleham alive.