The White Mage didn't snap out of his madness, but he did sign the letter they needed. The group left, and managed to acquire the stable boy. They took him to the blacksmith, who, after some persuasion, took the newly free man into tutelage, saying that he would allow him to marry his daughter if he was good enough. He told Cain where the Scout's Guild (the older thieves' guild) was.
The group found only a regular house where the guild was supposed to be and almost left. Cain, however, noticed a dagger attached to the fake "mother's" leg, and a fight broke out. Bill was disarmed, and Cain soon killed the first thief. They entered the house, where they were ambushed. After a gruesome fight against the hidden assassins, (Bill almost died and Cain spent most of the fight blind) they emerged victorious. They found stairs that led to a secret basement, but decided to check out the second floor before venturing down.
They found a magic circle there in a open space. Only Cain could see its true nature: it was a portal to another plane. Nathan foolishly entered it, and was taken away. The gate was then closed, separating the group. Cain and Bill found themselves suddenly in a normal room, with a sleeping person on a bed. The magic that sustained the "ritual room" upstairs was gone. After a brief fight, the guild's leader arrived in the room. He explained that the city always functioned with the Scout's Guild, and asked the pair to kill the other guild's leader. They accepted. He told them that the Blade's Edge would be attacked that night, and that the attackers would probably know the Cold Blood's hiding place.
Meanwhile, Nathan found himself in a vast desert. A beautiful, naked girl was the only other living being there. She walked away, and he followed. They reached a temple, where he entered. It was clearly magical. He met three challenges, and had to sacrifice his equipment, while he met negative aspects of his personality, each represented by a person that changed his life. (guilt as Cibele, arrogance as Arvam and doubt as Cain. Each guarded by a different god: Siren, Leviathan and Shiva.) As he triumphed over each, he got closer to whatever waited inside.
In the regular world, Cain and Bill protected the Blade's Edge, capturing a ninja alive. After extracting their base's location from him, they went to the graveyard, where it was located, to kill Cold Blood. Hell Lotus joined them again before entering the Assassin's Guild base. After killing some guards, they managed to face the traitor ninja leader. A difficult fight ensued, but they emerged victorious, thanks to a coordinated attack.
Nathan met the final guardian: himself. He was asked to sacrifice something important to him. After some thought, he blinded himself, carrying his eyes in his hand as he entered the final challenge. He met Bahamut inside, and tried to fight it. He was defeated, but his determination seemed enough to satisfy the god. He was allowed to proceed. He tripped on a sword carved in a rock. After rubbing his eyeballs there, he freed the blade and found himself back on the Scout's Guild. He discovered that he no longer had eyes, but could see while his new blade was close to his body.
Hell Lotus left with Cold Blood's blade to prove his death to her clan, while Bill and Cain went to the Scout's Guild to collect their reward. They found Nathan there, and were shocked to see him without even eye sockets. Nathan tied a strip of cloth around his head to spare the world from his condition, and it didn't seem to hinder his strange new vision.
They went back to their inn, after receiving a Thief's Glove from the guild leader as a reward for their job. Nathan allowed Cain to examine the blade that he acquired with so much sacrifice, and Cain discovered that the words "gods' final gift to men" was etched on the dull blade.
So. The plot thickens.