Thalassia is an island in The Skull region of the Wushanko Isles. Sulphur is mined here to make gunpowder. The highest point of the island holds the khan's jade palace. The Khan of Thalassia is a cruel man named Tombi. During 'A Jade Frog in the Throat', you help Ling, a young assassin, kill him and replace him with another man. Cave Giants are found here. Home to Thalassus.
The player may have a sailing outpost here.
- In A Friend Indeed the player sends a ship to make contact with a canny fisherman from Thalassia who knows the area moderately well.
- In West Meets East the player sends a ship to intercede in a fight between guards belonging to Thalassia's khan and a group of wizards from the Wizards' Tower, who've accidently teleported onto his land.
- In Expansion the player sends a ship to capture a small outpost, belonging to exiles, near Thalassia, to turn it into a sailing outpost.
- In For the Good of All the player sends a ship to destroy the ship of a particularly brutal exile that is vulnerable, believing it will make the area around Thalassia safer for all.
- In Troubled Waters the player sends a ship to find a quicker route to Thalassia.
- In The Cave Giant the player sends a ship to fight rogue long-armed cave giant has been spotted near a gunpowder factory on Thalassia, for fame and glory.
- In A New Home the player sends a ship to help evacuees, fleeing from the khan of Ai Jei, to establish a small colony on a tiny island near Thalassia.
- In Escort Duty the player sends a ship to escort traders from Thalassia on their journey to Ai Jei.
- In A Voyage of Discovery the player sends a ship to Thalassia to teach their captain to be Eagle-Eyed.
- In The Forgotten Scrolls the player sends a ship when they learn the Convict has been informed that a rare piece of a forgotten scroll is stored in the vault of a small bastion near Thalassia. Help him raid the bastion to claim it. His attributes will prove vital for success.
- In The Forgotten Scrolls the player sends a ship when they learn the Memory has divined the location of a forgotten scroll, but it is protected by an anima barrier. Head to Thalassia to claim it.
- In The Forgotten Scrolls the player sends a ship when they learn the Biologist believes she knows the location of a supply of gunpowder. Help her evade the native long-armed cave giants of Thalassia and claim it.
- In A Joint Acquisition the player sends a ship after learning the Whaler and the Biologist have tracked down a big surplus of gunpowder in a deserted port city near Thalassia that is surrounded by flying squid. Their knowledge of sea creatures is essential to retrieve these resources.
- In A Jade Frog in the Throat, The Assassin goes to Thalassia to depose Khan Tombi with the player's assistance.
- The beast that the player encounters during the Deadliest Catch quest, Thalassus, is thought to be native to the waters surrounding this Island.