The prophecy of Sekolah

Ending the Sahuagin Civil War is an optional Main Quest in Baldur's Gate II: Shadows of Amn that takes place at the end of Chapter 4. It leads on directly from the quest Getting A Ship and itself leads on to the start of Chapter 5.

This quest begins when the party is taken to the Underwater City by sahuagin. Here, King Ixilthetocal will first make the party prove their might by slaying an ettin in the city's gladiatorial arena, and then direct them to seek out and kill Prince Villynaty, leader of a rebellious faction of sahuagin who are fighting a civil war. To prove the deed is done, they must bring him the prince's heart.

The party will be directed to the Temple of Sekolah, where the new high priestess will tell the players that she believes the rebels are in the right. She begs them to at least talk to Prince Villynaty, and gives them a Rebel Orb as a sign of safe passage - this doesn't prevent the party from having to fight the bands of Sahuagin Rebels that wander the map, however.

To reach the rebel base, the player must first acquire the Tooth of Sekolah from the Spectator in the Drow Ruins, past the area with the side-quest Riddle of the Imps.

Upon arriving at the rebel base, if the player has the Rebel Orb, they are ushered into the prince's presence, where he asks for them to double-cross the king; he will give them a sahuagin heart for them to present as his own, and then launch a sneak attack on the king.

The player must then make a choice as to which side they will fight for. Siding with the rebels grants more quest EXP (60,500 EXP vs. the 58,500 EXP for siding with the king), but Prince Villynaty carries the unique items Wave Blade and Gauntlets of Crushing. However, siding with the Prince gives the player the chance to pickpocket these items from him before departing, so it is arguably more profitable to side with him.

The player can also just kill every sahuagin in the city, but this is a very challenging fight.

Regardless of which path is taken, the player will gain access to a Magical Rope that can be used at an opening in the rebel's base to descend to the Underdark, ending Chapter 4 and beginning Chapter 5.