Nicholas Sayre and the Creature in the Case is a short story entry in the Old Kingdom series by Garth Nix. A follow-up to Abhorsen, it tells of Nicholas Sayre's encounter with a Free magic creature in Ancelstierre and his return to the Old Kingdom. Published initially as a stand-alone story for World Book Day, it was later released as part of Nix's short story anthology Across the Wall: A Tale of the Abhorsen and Other Stories.