Having obtained the Urn of Orpheus, Lyra, Aeron and Gerald Severus decided to head into Hades, which they achieved by gaining the favor of Thanatos, through freeing his sister Atropos.

After passing Charon, Cerberus, and Minos, they reached the Asphodel Meadows, then the Pit, watchtower to Tartarus where Lyra tricked the Cyclops Polyphemus into leaving his post. Aeron sent his Soul into Tartarus, attempting to retrieve Allan, but instead ended up stuck, and had to make a deal with a Titanspawn in order to escape - that Titanspawn was Apophis, Avatar of Nyx, Titanrealm of Night, and it allowed him to also drag the Soul of Allan out of Tartarus. After this, Gerald Severus also sent his Soul down, dragging out Erela, a Titanspawn that Dionysus told him could take them out of the Underworld.

After her companions freed Allan and Erela from Tartarus, the Titanspawn opened a portal allowing them to escape back to the World.