She first appears in one of Percy Jackson's visions at Medusa's old statuary, where she is conspiring with Kronos about the 'nasty surprise' in store for Percy and his friends, and was furthermore tasked with notifying Hyperion of a troop movement to Central Park. Later in the battle, Queen Sess finds herself fighting alongside her master as he confronts his son Chiron. Sess becomes impatient and charges, foolishly believing she would be able to catch Chiron off guard, and is rewarded with a direct pass to Tartarus via one of Chiron's arrows shot directly between her eyes. She left behind her armor as a spoil of war. However, her premature attack on Chiron actually helped the Titan king because Chiron had to use his last arrow on her, which meant he would have to confront the Titan king using a sword, which he did not like.
- Although Queen Sess' character appears not to come directly from any mythological background, due to her status she might be inspired by the Dracaena Queen from the Hercules myth. Also, though her character plays an important role in incapacitating Chiron, her actual name 'Sess' is only said once by Kronos throughout the whole book and she never comes in direct contact or battle with Percy. Throughout her final scene she is simply referred to as the 'Dracanae Queen'.
- Sess means weed, maybe because of some connection between her and the sea.
- She is the first of two dracaenae mentioned in the series by name, followed by Sssssarah in The Trials of Apollo.