Blackreach turned out to be an immense, naturally lit cavern; the ceiling glowed with streaks of blue bioluminescence. On the ground, towering mushrooms added a diffuse blue light to the area. They were swaying, though there was no wind to speak of. Spores floated so thickly that they turned the middle distance into a teal fog.

Serana and I used linens to form masks over our mouths and noses. The Falmer down here seemed to be breathing the air just fine, so I wasn't worried about the spores doing anything horrific when inhaled. I could, however, feel faint itchiness in my nose. In a cave where hostile creatures hunted by sound, I didn't want my cause of death to involve a massive sneezing fit.

We entered Blackreach in the northeast corner, with the first lift just a short distance to the south. This, I realized, was probably the lift that we had been unable to enter back on the surface. Directly across from the entrance was the first of many buildings scattered throughout the cavern. There was a relatively new sign outside calling it 'Sinderion's Field Laboratory.'

We spent our first night here, locking the door securely behind us. The skeletal remains of poor Sinderion lay just inside the door, riddled with arrows. According to his journal, he had been an alchemist fascinated with Nirnroot and had come here in search of a rare strain of them. By the looks of things, the Falmer had taken offense to his peaceful attempt to exist among them.

It took several days, and all our food, to finally grasp how big the cavern really was. The place was occupied by camps of Falmer and Chaurus. We were forced to do a lot of hit-and-run tactics while raiding for food once ours ran out. The underground streams and large pools had a variety of fish that were being farmed by the Falmer.

Sindarion's home had a book called "Chaurus Pie: A Recipe." We hesitated for a week before trying that. It was… oddly not that bad. Of all things, the white, thick meat from the midsection of the Chaurus tasted vaguely of seafood; slightly salty, and mildly fishy. It reminded me a bit of the shrimp from the Bay of Tava back in Hammerfell. Both of us pretended as much, calling it Cave Shellfish whenever harvesting it for dinner.

I was soon craving fruit, bread, and cheese, as mushrooms, grilled Chaurus meat, and fish became common meals for us. But we both made due, and Serana was able to hunt down the occasional Falmer for her own needs.

We found three shafts where we could have taken an elevator back to the surface. I took to drawing a rough map of the place just to keep from getting completely lost. I realized that each elevator up was an exit point in one of three different holds. Each one was only a few hours' travel from a major town. It was disturbing to think that if the Falmer could have figured out how to work them, they could overwhelm the citizens in a single night.

Thankfully, the blind beings showed no sign of interest in the control panels outside each lift. The technology itself was beyond my understanding, but there were only a very limited number of buttons. I figured I could fumble my way through getting them to work for me if it came down to it.

Several buildings had served some purpose or other long ago, and we found the ruins of a Dwemer city. We peered inside, then skirted the place cautiously. Neither Serana nor I wanted to tangle with the Falmer and Chaurus crawling around in that small citadel. Things were dicey enough just skulking on the fringes.

I also got to learn more about Chaurus than I ever wanted to know. The earwig cockroaches stayed that way for a while, only to later wrap themselves in a chrysalis. After a while, it would explode out of its -well camouflaged- cocoon, spraying goo in all directions. It would then be sporting the flashy new look of a praying mantis crossed with a mosquito. Having one of those huge bastards explode into the air right next to you and taking an awkward but aggressive flight is enough to give you nightmares for weeks. Take my word for it.

Eventually, we found the place that Septimus had told us about; the Tower of Mzark. It was in the far southwestern corner of the cavern, between two waterfalls and across a stone bridge. Once through the doors, we found ourselves in yet another lift.

The tower was, thankfully, unoccupied. We passed a long abandoned camp complete with bedrolls and a campfire that was set and ready to go, but had never been lit. I couldn't help but wonder who the heck had brought it down here. The question was answered through another door marked 'Oculory.'

We wound our way up a ramp and found ourselves perched on a huge Dwemer device; some sort of huge sphere encased in concentric rings. Above it were several glass lenses that were fixed on the ends of metallic arms. Light shone down from the ceiling. A raised podium had several waist-high pedestals, some sort of plate with a diagram of light. There was also a spot that I could only conclude was for the square Lexicon that Septimus had given me.

Below the podium lay the skeletal remains of someone named Drokt. His journal revealed his obsession with the Oculory device, but he had died before figuring it out.

Serana studied the plate with interest, "Okay, the bad news is; I don't read the Dwemer language."

I let out a breath, "Okay."

Then Serana smiled, "The good news is that the Dwemer were a very logical people and saw no reason to over-complicate things. They've made diagrams that I think I can puzzle out. Go ahead and put the cube in the receptacle."

It clicked into the spot with ease, long tines closing around it to hold it in place.

There was a hiss of steam and the plate diagrams changed. Two pedestals on the right opened small shields to reveal glowing blue buttons. Serana eyeballed them and nodded. "Looks like our friend down there got it partially set up. Don't touch the button on the far right…. Push the next one over."

"Here's hoping that I don't go the route of Helskr," I muttered, pressing the button. Neither of us commented on how quickly I yanked my hand back.

The concentric circles on the gigantic sphere separated, flipped, and settled again.

"Again," she narrowed her eyes as the diagram changed before her.

I obeyed, yanking my hand back as there was another hiss of steam. The entire sphere rolled over in the device while the rings did another flip-dance. Lenses were revealed when the sphere stopped.

I pushed the button twice more at Serana's direction before she held up a hand, "Stop."

A button on Serana's left side had suddenly lit up, and with a click, the square lexicon opened like the hull of a nut. Inside, a glowing square inside the shell was revealed. She turned to eyeball it, and then the diagram some more.

"Push the one that just lit up," she pointed to the button to her left.

The lenses on the arms above the device moved this time; spinning, shifting to a new configuration, and then settling. I pushed it a second time at her direction and they moved once more. This time, the light source in the ceiling began to shine through the lenses, making several beams of light land on the sphere below.

The final button on the left was now revealed and glowing. I pressed it.

The lexicon clicked, the shell closing back over the core. The lenses separated and swung to the edges of the room. From the center of the ceiling, a large oval shape sank, surrounded by several tiny lenses. The large oval split down the middle and opened to reveal the familiar large white tube. The square lexicon had darkened from a metallic brassy sheen to something black, shot through with tiny etchings of blue light. The tines retracted, leaving the square cube free.

"I hope that means that this thing got inscribed with the right information," I muttered. I pried it out of the receptacle before jogging down to remove the Elder Scroll tube from the machine. "So now what?"

"Now, we're done," Serana let out a relieved breath. "Let's rest, and then see where the lift takes us."