We continue to descend into the sewers, and are surprised when crossing a bridge by a hideous adolescent otyugh (they like poo), and swarmed by roaches. The rushing waters of the sewer were unsurprisingly toxic, and wading through them often caused more fatigue and damage than the monsters themselves.
We move on, after fishing a dwarven corpse out of the sewage and recovering magical possessions from him. We discover arcane runes in elvish pointing the way to a library, signs we handily follow into tunnels that lead away from the sewers. We hear the sound of dripping water on worked stone, the origins of such stone being dwarven, elven, and human, just the same as those who hold the three parts of the key.
Fungus crawls along the walls, which erupt into a crazy fungus plant thing which we slaughter in our startled mercilessness. The library waits just beyond for us to explore, but is adly filled with more livid mold and myconids.