The Sedna Abyss is a whirlpool where the ship on which Pavetta and Duny were traveling was lost at sea during a magical storm, caused by Vilgefortz. The abyss is located off the coast of Cintra, in the Great Sea.
- It turns out much later in the story, that Pavetta and Duny's ship wasn't the first ship, which disappeared in the Sedna Abyss. In The Tower of the Swallow, Jarl Crach an Craite told the sorceress Yennefer about the natural dangers of the abyss, when she was searching for Ciri.
- In her research, Yennefer found out, that a person teleported from Thanedd during the Thanedd coup and ended up in the Sedna Abyss for some reason. She suspected, it was Vilgefortz with Ciri.
- There was a portal to the citadel of Stygga, which was the hideout of Vilgefortz. Many ship wrecks ended up there.
- This fictional location shares the name with the mythological figure, Sedna.