Kaocho Palace was initially built by King Wo after the city was founded. For unknown reasons, King Wo chose to build the palace on top on of ancient ruins, the Ouroboros labyrinth. The palace not only served as the personal residence of King Wo, but as his center of government. Thus, his advisers Meisa, Kan-Shuku worked there.
During their travels, Matthew's party of Adepts comes to Kaocho for several reasons. They are not only searching for a way to enter the Ouroboros to obtain the Sol Mask within it, but to find a way into Ayuthay. Ayuthay had been under attack by Kaochan soldiers, who would only accept orders from King Wo.
Matthew's party is allowed into the Palace after the guards learn that the group consists of Adepts. In the throne room, the Adepts hide and overhear a conversation between Wo, his two advisors, and Chalis, who they quickly associate with Blados. Chalis's personal soldiers force the Adepts out of hiding, and informs them of the Sol Mask hidden in the Ourboros. King Wo requests that the group enter the Ouroboros, get the Sol Mask, and bring it to him, as he wishes to wage war with it. However, King Wo's advisers suggest that the group assist in the siege of Ayuthay. This plan is approved of by King Wo, and Meisa writes up a letter granting the Adepts entrance into Ayuthay, which is given to Matthew. The group, particularly Tyrell, is putoff by the request, and refuse. Out of anger, the King orders the Adepts removed. Kan-Shuku then opens a trapdoor below the Adepts, which causes them to fall into the heart of the Ouroboros.
During the Grave Eclipse, the few remaining Kaochan survivors of the monster attacks are brought into the palace with King Wo. The palace is firmly locked and apparently remains safe. However, the ultimate outcome is unknown.
At the entrance of the palace, the guards will stop you and ask if you are Adepts or not. Say no to get away, or yes for entry into the palace. Once inside, there is a Herb from the warehouse on the right and the exit on the left leads to the maze.
Head up into the throne room to see the King with a shifty-looking character named Chalis. After a long conversation, The King gives the player Wo's Letter, saying that Matthew and his friends will help his siege of Ayuthay.