All the Dust that Falls: A Roomba Isekai Adventure

As Beatrice rounded the corner towards the library, the demon made to follow. But I met it as soon as it started up the stairs. This time I didn't hold back. There was no concern for preserving the carpet. I just had to ensure that it was stalled long enough for Beatrice to get away. The demon seemed to have figured out the futility of attacking me. It also couldn't just sit at the base of the stairs. It didn't seem capable of going through any side doors and hadn't even tried to leave the castle. So the demon's only options were to be slowly drained of all of its mass until it was no longer a threat to anyone or make a break for it.

It charged at me, seemingly intending to barrel past. As obvious as the intention was, there was little I could do to block its advance. The only thing I could do was stay close to its feet, consuming matter as it ran. I considered transmuting a few more of the demons inside my dustbin, but I didn't think it would do much here. For one, there weren't as many demons inside me now, and two, I didn't want to destroy the castle. The carpet damage from my overpowered vacuum was one thing, but bringing down walls might damage Beatrice as well.

It made it to the corner Beatrice had turned, but I was right on its heels. Already the creature was down 20% of his total mass from when we first met. I was pleasantly surprised that the process was accelerating. It seemed that the less powerful it was, the less it could resist the pull of my vacuum.

The demon seemed to realize it wouldn't catch Beatrice or escape me. So instead, it turned all its might into another attempt to crush me. It flailed about randomly, slamming with both fists into the stone floors, just to smash into me. I tried to dodge, but its slightly decreased size brought a degree of maneuverability it previously lacked. Despite my best efforts, I couldn't get it down more than another 5% before a blow sent me tumbling away. I felt part of my outer shell crack as I rolled sideways. Soon, I came to rest upside down. And I surely thought this was the end of me.

Being on my back was a mostly unfamiliar experience. It had only happened once, and I didn't like thinking about it.

I lay there on my back, waiting for the demon to come and smash me. However, I wouldn't go down easily if this was the end. So I turned my vacuum up as high as possible for a finishing blow. A cyclone of debris and dirt raged above me, the poor carpet flapping upwards in protest. Yet despite all that, my sensors didn't detect an incoming blow. It only took me a tenth of a second to realize that the demon wasn't coming toward me. In fact, it was running away. It seemed that it would take advantage of my helplessness to escape.

Which left me in a bit of a strange, anticlimactic position. I turned down my vacuum. What more could I do? I wasn't like a turtle that could rock around enough to flip over. I didn't have that sort of mobility. Though just to make sure, I wiggled my wheels around a bit. Nothing happened. Dang.

Oh, wait, maybe I did have an option. In my panic, I had forgotten about how much I had changed. I was no longer the same creature that had come to this place. So I popped my grabby arm out and used it to push off the ground. It was rough since it wasn't quite long enough to flip me over completely. But between that and a decent amount of wiggling, my wheels soon touched the solid ground again.

I glanced around and regained my bearings. In the distance, I could see the shrunken demon running down the hall. Hesitating, I considered my options. Should I follow it and finish it, or should I make sure Beatrice is all right?

I glanced down the hallway Beatrice had retreated to. The library wasn't far off, and I hadn't heard any more commotion from that direction. She was probably fine. Taking another glance at the disastrous mess along the hall, I swiveled and raced after my foe.

—-

Bee couldn't tell what was going on outside the library. There were some faint noises but not loud enough to distinguish anything specific. She hoped her master wouldn't be too disappointed with her for running away, but it seemed to be the only logical option. Every other path led to fighting an enemy she couldn't win against.

Well, couldn't win against them yet, anyway. At Bee's current pace, that might change sooner than she could have dreamed. However, in the meantime, she found some interesting books that might help. She set another pile on the table and surveyed her newest collection. On the left were manuals covering advanced potions of speed and strength. Those might help her survive in the immediate future. On the right was a stack of tomes on earth demons. They were a common enough type of demon that there was plenty of information for her to comb through. Sighing, Bee slumped gratefully into her seat and selected a book to her right.

Apparently, earth demons had a weakness to water. Specifically to large amounts of water, actually. One of the many advantages of having a body made entirely of earth was that you could shift it around so that lost limbs and the like could quickly be replaced. Meaning that it had no particular weak spots. However, when wet, the mass couldn't be shifted around as easily. This left the demons vulnerable. It also allowed for larger chunks to be broken off all at once.

She also read that if you could freeze the wet part, you could shatter large amounts of it more efficiently. This was a demanding series of actions to pull off, however. Plus, if you were skilled enough to pull a stunt like that off consistently, you were likely powerful enough to defeat an earth demon without resorting to such tricks. At least, that's what the book said.

It was apparent that swords, spears, and other bladed weapons were essentially useless against these demons. Even axes weren't recommended. Much more effective was a hammer or something that could really knock off large chunks at once. The most challenging part was preventing the lost mass from being reabsorbed by the demon. That was often where the water came in.

Bee considered her broom. It wasn't a hammer, but it was quite literally designed to remove dirt and debris. Of course, it depended on how tightly the dirt was packed, but the broom end could sweep apart significant bits of sand or earth-like material with each swipe. On top of that, it would do a decent job of scattering that material. With Void's ability to consume matter, she shouldn't have much trouble keeping the lost mass away from it. As long as she had her master by her side, that is. She didn't think Void would have any problem with helping her in such a way. Plus, monsters that were literally made from dirt seemed to go against everything Void stood for.

Bee paused in her reading. Actually, that didn't make sense. Why would Void release these demons, of all things? It could have easily kept these locked away and released the other demons for her training. Was it possible that it didn't know what was released at the time?

She considered that Void might just have known the power level of these demons and not their species. It seemed possible. She thought that Void wasn't likely to intentionally release this level of debris and destruction across the castle. However, that called into question even more things. If Void didn't know that, what else didn't it know?

Setting aside those doubts for later, Bee continued thumbing through her books. She definitely needed to restock her supply of speed potions. Those had saved her life and allowed her to keep up with the thing. She also found a recipe for a freezing potion that could be hurled at an enemy. She'd have to do some testing to determine the range of effect and power, but the ingredients were not super complicated. She would have to figure out how to get into some storerooms where the more valuable components were kept, but that shouldn't be impossible. She was pretty sure she knew where a couple sets of keys were.

Besides speed and freezing, she needed a way to get the earth demons wet before freezing them. Running through imaginary combat in her mind, Bee frowned. Actually, freezing might not be the best idea. She would need to crush the frozen part of it to complete that combo, and her broom wasn't meant for heavy hitting. It would probably break against anything less brittle than bone. That's not to mention that she still wasn't the strongest herself, though strength potions could help with that temporarily.

So she would need a hammer and to be in range to strike it. Glancing down at the small meat tenderizer in her belt, Bee shuddered. That didn't seem like the best idea, even with greater speed. She definitely needed to think about it a bit more.

A loud growl interrupted her musings, and Bee sat bolt upright. The good news was it was only her stomach. The bad news was that she was getting quite hungry and thirsty again. Bee set aside the books for the moment in favor of her more immediate needs. She needed more food and water. She had to at least make a trip to the kitchen pretty soon. Maybe she could grab alchemy supplies at the same time. But without Void's help, would she be able to make it?

Bee considered. Well, she was much more capable than before, not to mention at a higher level. But now, there were also more than just lesser demons roaming the halls. However, the catacombs had helped her understand Void a bit better. While her master had thrown her into difficult situations before, it had never put her in an impossible situation without backup. She didn't think that Void would let her come to harm, so it seemed unlikely that it would make her travel alone in these conditions. She had someone to watch her back, and she didn't have to take the same risks she did before.

So before going out there, she needed to wait for her master to return. She hoped it wouldn't be that long. She was starting to get thirsty.

—

It didn't take me long to catch the demon. I didn't try anything fancy. I just stayed outside of its crushing range and let my vacuum and sanitation lamp do their work. Already it was significantly smaller than it had been. When it realized I was too fast to outrun, it gave up on that plan. Instead, it returned to just charging at me futilely. I kept dodging to the side, leading in a large circle.

I spent my time leading it on our merry chase, trying to stay in the same area. I didn't want to get too far away lest there be other mess makers like this one. They might see us and join in on the fun. That wouldn't be great. Well, it seemed that I could take this beast on alone with some planning and caution. But I only wanted to try to take on one at a time right now. Perhaps it would be a different story once I had a chance to train up my sanitation lamp and vacuum power.

This dance continued for a few minutes, but eventually, I prevailed. The creature shrank enough that I didn't worry about it hitting me. Satisfied, I got in close and turned my vacuum up. The whole thing dissolved in a couple more seconds and flew harmlessly into my dustbin.

I was curious to see if it was still moving like the other demons I had absorbed. Checking in on my dustbin, there were still four lesser demons inside. There were also a bunch of other things, things with energy that felt different from electricity. They felt more similar to the demons than anything else. The sheer amount made me think it was related to the army of skeletons I had consumed. But I could also make out the remains of the earth demon separately. It was scattered everywhere, but I could somehow recognize that the scattered parts belonged to one entity. I considered transmuting it for energy. I had used quite a bit during that battle, after all.

However, as I consumed it, I noticed a large number flit across my vision. By this point, I had associated the numbers with cleaning activities, but now I considered their meaning. Maybe it was telling me the amount of energy I had absorbed?