Gleipnir (グレイプニル Gureipuniru) is a Dark Magic tome from Fire Emblem: The Sacred Stones. Alongside the Black Axe Garm, Gleipnir is one of the Sacred Twins of the Empire of Grado. This tome is presented to Ephraim by Knoll after the latter discloses the truth behind Grado's invasion, where he reveals Lyon's desperate attempts to acquire the power to heal his ailing father.
According to Norse mythology, Gleipnir is the strongest rope ever created, forged by the dwarves to keep the wolf Fenrir bound. This rope is prophesied to break at Ragnarök, whereupon Fenrir will exact his revenge upon Odin for keeping him bound to his throne.