Sigurd Changing Shape with Gunnar to Ride the Fire for Brynhild
To help his blood-brother Gunnar marry the Valkyrie Brynhild, the hero Sigurd uses magic to take on Gunnar's appearance. Only Sigurd and his horse Grani are capable of crossing the magical wall of fire that protects Brynhild's mountain hall. This deception wins the bride for Gunnar but ultimately leads to a tragic end for all involved when the secret is eventually revealed.