Wait

You're about to enter the vent when you realize something.

"If Weiss had the map, then why did I find her in an area nowhere near the vent?" You think. "Or anywhere on the path to the vent? She was caught in that room, so she couldn't have been dragged off course, and I doubt she just wanted to explore without a reason... Why was she over there?"

Your mind races, and then suddenly everything makes sense.

"This... This vent is the obstacle... This vent is a trap! It's why no one was able to get to the bottom! It's because from the very start, the map was deceiving us!"

Everything started to clear up now. Alex must come down here at some points. She had to deposit and feed her experiments, after all. She would know about all the victims. She was the one that "leaked" the map into the maiden hall in the first place... If girls had a secret exit, then that reduced the chance of them finding an alternative way out! Not to mention, the experiments must be the fetish of many people. However, in order for them to perform, they needed prey. So there must be a few hidden cameras in each of their lairs... She used the dungeon to dispose of troublemakers, and create fetish porn at the same time!

"That... That BITCH!" You exclaim.

"Well, I won't have it. There must be another way out! Something Weiss didn't think of!"

You look at the map. You spot a staircase, but it's on the other side of the spider room.

"So that was Weiss's plan... Sorry, but that's not going to work." You keep looking. After about ten minutes of looking, you conclude that there's only one option. The elevator shaft.

An hour later, you're standing at the foot of the elevator shaft who's doors you pried open with a candelabra. It spans down into an inky-black abyss, with no bottom in sight. You feel dizzy just looking at it. You've made a makeshift rope from the clothing making up the gorgon's bed. It's about 20 or so feet long. Not enough to reach the bottom, but it should be enough to reach the door of the second floor. You can see from here that the second floor elevator doorway doesn't have a door. Alex must have not deemed it necessary.

"Good." You thought to yourself. "Cutting corners will be her downfall."

You tied the makeshift rope to a nearby doorknob and started your decent. You felt physically ill. You gripped onto the rope with every ounce of strength, and tried to carefully and slowly make your way down to the open door. You made it about halfway down.

Suddenly, the light from the doorway above you dimmed. You looked up, and saw a shadow. Standing about 5 feet above you was the Naga. You had considered yourself lucky that you had never run into her, but she couldn't have come at a worse time. Her eyes burned with a furious hatred, and her fists were clenched. You didn't even notice her nudity as it was completely overshadowed by her horrible aura of menace.

"You..." She growled. "You KILLED Asuka... You gutted her... Ripped out her beautiful eyes..."

You rapidly started climbing down faster, but it was no use. The Naga lay down next to the edge, and brandished a bread knife. No doubt a weapon from a girl she had encountered. She took it, and put it to the rope.

"I look forward to hearing your body splatter against the ground... Have fun in hell, bitch."

The rope did not last long. After a few seconds of sawing, you heard a "SNAP!" and felt the rope go limp. You felt fear in your heart, staring up at your assailant as she glared at you with piercing snakelike eyes as you fell into the lightless void below.

......

Your heart missed a beat. You narrowly dodged a bread knife thrown at your head. It was a good 20 second until you heard it clang loudly at the bottom of the shaft.

You had managed to grab the doorway of the elevator shaft.

A furious naga raged and cursed at you, before panicking and going to look for more things to throw at you. You clambered up into the doorway before she had the chance. You brush yourself off as a plant pot flies down the elevator shaft behind you. You make your way further in. The entire place looks pretty much untouched. You give a sigh of relief. Aside from the trap at the end of the vent, it appears as though there weren't any more experiments. You pull the book out from between your cleavage, and make your way down to the control room.

You don't encounter anything on your way downwards, but you keep an eye out all the same. You wouldn't put it past Alex to put a last resort defense near the end. Thankfully though, that doesn't seem to be the case. After about half an hour of traveling down, through the unlit dungeon, you reach the final floor. Right below you is the control room. You make your way over to the elevator shaft, and look down.

It's about 20 feet the next floor. You take a deep breath, and jump.

"BANG"

The steel of the elevator shaft floor vibrates between your feet. You don't take the impact well. You smash your hand on the side of a strange chunk of steel jutting out from the center and slip backwards. Your hand is immediately sprained and your ankle is badly twisted. Other than that though, you seem to be alright. You managed to avoid the broken shards of plant pot and bread knife, avoiding laceration.

With great difficulty, you struggle out of the elevator pit. It's about 5 feet deep. Your hand hurts like hell after climbing out, so you grab it and hold it in your hand for a minute until the pain starts to relax.

You look around the room. The entire thing is lit up by screens and computers. In the center of the room is a loud, gigantic generator about the size of a small bus. You'd done it.