His mother is a shape-shifting trickster god and his father is a giant's workhorse. This deep dive treats Sleipnir, Odin's eight-legged gray horse, as the subject of a serious narrative biography, beginning with the cosmic construction contract gone wrong: a mysterious builder who demanded the sun, the moon, and Freyja for building Asgard's wall, the stallion Svadilfari who did twice his master's work, and Loki's desperate transformation into a mare.

We follow Sleipnir's exploits across the realms, from the race that lured the giant Hrungnir straight through Asgard's gates to the gallop over open ocean and the nine-night descent into the underworld to plead for Baldr. Then we ask why the Norse gave this horse eight legs, weighing the Indo-European twin-horse theory, the shamanic spirit-steed theory, and the haunting funeral-bier theory of f ...