Final answer:
Hermod visits Niflheim in Norse mythology to retrieve his brother Baldr's soul.
Step-by-step explanation:
According to historical accounts, Hermod visits Niflheim in Norse mythology as part of a journey to retrieve the soul of his brother Baldr. Niflheim is one of the Nine Worlds in Norse cosmology, often associated with an icy and cold realm. Hermod's visit to Niflheim shows his bravery and determination to bring Baldr back to the land of the living.