According to Snorri Sturluson, Hermod is the son of Odin and Frigg. Except for the tale of the death of Baldr (which may be a late addition to the original myth, under Christian influence and inspired by the death of Jesus, with Loki as the devil), Hermod is mentioned only briefly in a saga of the Skaldungs.
Moreover, Eyvind Skaldaspillir has him and the poet god Bragi receive the fallen king Haakon the Good in Valhalla. Hermod was - unlike most other god names - a common personal name, used by both northern and southern Germanic people. The legendary hero Hermod may have been a real person, honoured by posterity with a seat in the circle of the gods.
Referred to as "Hermod the Furious", he was sent by Odin to Hel to bargain for his brother Balder's release. Odin's horse Sleipnir was brought forth, and Hermod rode for nine nights through dark and deep valleys, seeing nothing until he came to the river Gjøll and the bridge over it, the Gjallar Bridge, paved with shining gold.
The maiden Modgunn, who guards the bridge, told him that the day before five companies of dead men had ridden across, "but no less does the bridge thunder beneath you alone, and you have not the sound of dead men. So why do you ride here on the Hel Road?" Hermod explained his errand, and she told him that Baldr had ridden past the day before, "but the Way of Hel leads down and north." Hence the Norwegian expression "going north and down", when something goes wrong, "going to hell".
Hermod reached Hel's gate and gave Sleipnir the slip, so that he jumped so high over the gate that he did not even touch it. Hermod dismounted and entered the hall, where Baldr sat in the highest seat. There Hermod spent the night with his brother. In the morning he asked Hel to let Baldr ride home with him.
But Hel wanted to see if Baldr was as loved as Hermod claimed. "If all things in the world weep for him, he shall come back to the Aesir; but he shall stay here, if any speak against him, or will not weep."
Baldr followed his brother out of the hall and gave him the ring Draupnir as a memorial to their father Odin. Back in Asgard, Hermod told of his journey, and the Aesir asked the whole world to weep Baldr out of Hel.
But when the messengers spoke to the giantess Thokk in her rock cave, she said: "Neither living nor dead does Odin's son honor me. Let Hel keep what she has!" So Baldr never returned to the world of the living; and Thokk is thought to be Loki disguised as a giantess.