As the Warlord and Drow had gone for a swim, Mouse and Chuck entertained themselves by sitting around on the stairs and then exploring the tower for anything they might have missed the first time. The other two had been gone some time, and they were carefully examining the mouldy remains of books in the library for anything still legible when they heard footsteps on the stairs - coming down from above.
Hiding behind the door, they waited until the footsteps stopped outside, the door swung open and....Dungeon Master walked into the room. He looked round and spotted them, and then, as if the incident where he was their captive until he escaped never happened, proceeded to tell them the Warlord and Drow had been captured by some Kua-Toa and would soon be executed. He then failed to dissuade them from mounting a rescue mission - his insistence that they should go and "get revenge" on the Magus instead was duly ignored as Chuck at least didn't quite trust him. Funny that.
With some difficulty, they managed to swim through the tight passageway and emerge gasping for breath in the flooded cavern. They followed the tunnel above ground to a T-junction and, with no clue as to which way the others might have gone, decided to left-hand map. Sneaking along, they soon spotted a couple of Kua-Toa carrying spears ahead, with what seemed to be the Warlord's in front, just disappearing round a corner. After debating whether to just attack or not, they decided to follow them for a bit.
Meanwhile, the Warlord and Drow had indeed met some Kua-Toa upon reaching the t-junction. As neither side immediately attacked, the Kua-Toa instead, jabbering in some language neither of the two characters understood, gestured for them to follow them. They pushed and poked and led the two down the tunnel to the right. While the Drow began to wonder whether the Kua-Toa thought they'd taken them prisoner, they emerged into a large cavern with several other of the fishy humanoids and were led to a crude tent. Inside they were given a possibly drugged drink and the Kua-Toa leader talked to them using a magic stone to translate into Common. Due to several misunderstandings, he concluded they were idiots obsessed with fish, but offered to take them to meet his god. They explained their other friends couldn't make it through the watery tunnel, and it was agreed that they would accompany the team sent to explore the last fork in the tunnel system to see if it led to the surface.
Sure enough, it did, albeit through a steep sink-hole that the Warlord was able to fly up through but would have been difficult to climb up. However, just as they were discussing going up to fetch Mouse and Chuck (and Cat of course) from the Bloodtower, those very persons spoke up from the shadows behind them and said "Hello!" Although they were annoyed that they'd had to swim when they didn't need to, the party were at least all together again, and happily not dead despite what Dungeon Master had said.
They accompanied the Kua-Toa group as they made their down to their home, travelling through the deep caverns for a couple of days. The Kua-Toa mostly stuck to side passageways once they got deeper, to avoid "trouble" they said, but one "awake period" the leader came to tell them that they needed to go on "the King's Highway" for a bit. It dawned on the party that they really were in the Underdark now. Despite the King's Highway's reputation as a treacherous path full of murderers, they had little trouble until one narrower part where, suddenly, chaos broke out and the party found themselves stuck between masses of fighting Kua-Toa, and facing a Blood Ooze.
The Ooze hurt badly, not least because it sprayed necrotic and poisonous blood everywhere whenever it was hit, and attempted to drain the blood from anything that stayed too close. But the party rapidly took it down, giving it little opportunity to hurt them. The Kua-Toa were less lucky.