SPOILER FILLED RANT/THEORIZING ABOUT THE RIVER, CARL, THE ALL-TREE, THE NOTHING, AND THE UNWASHED.
so the river is one of those parts of DCC that i personally find the most fascinating. idk why exactly it tickled my brain in just the right way to kind of make me obsessed with figuring it out, but it did. so i started rereading the entire series to, amongst other reasons, theorize on it.
carl hearing "the river" was first introduced in book 5, TBM, after carl used the ring of divine suffering for the first time. TIR has the passage "I felt the torrent under me. Not a river. It had never been a river. Voices. Screams. Nightmares distilled to light. Souls. And where was it flowing to? 'Down' was the answer. Always down. Why are they always screaming?" and then moments later carl hears grimaldi, who we know is part of the all-tree now, telling carl to look down because he's been standing in the river the entire time. the ai then gives carl an achievement that says "but you're currently a babbling idiot with your bare feet buried in an All-Tree root." so "the river" is a stream of screaming souls that make up a root of the all-tree. i think the ring of divine suffering was a catalyst to first connect carl to the all-tree, but that alone doesn't mean anything. we havent seen other characters who have used the ring mention anything about a river or hearing screams. sure, that doesnt necessarily mean anything cuz its possible they just didnt say anything about it (i dont think pony used it all that much before he ate it, damascus steel doesn't have a reason to tell carl about a river, and li na isn't exactly the sharing type), but i think it does mean something. baroness victory mentions primals having a "communal nature" which we know to be true in that they're a collected hivemind. so i think that carl being a primal made him more susceptible to mind meld connections, and that while the ring was a catalyst to connect him to the all-tree, he's as connected as he is because he's a primal. but in being connected to the all-tree, carl is connected to SOULS within the dungeon. idk if that includes those who lived before the dungeon or those who died outside of it, but i think that at least includes those who've died in the dungeon during the crawl. (i also think he's connected to more than just the souls who've died during this crawl, but i'll get to that in a minute)
during the warlord meeting in TIR, juice box turns into a creature of many names that is known as "the Unwashed." this creature is described as follows: "She went from a human to a thin midnight black alien creature with no arms but multiple tentacles waving from her shoulders. The form was similar to an armless soother alien, but taller and thinner." this creature is said to be the personification of the Nothing, and that there's scientific evidence that some people see the Unwashed before they die. now look at the art. kinda looks like a fucked up evil tree, doesn't it?
later, when architect houston is doing surgery on himself and a dead changeling, the changeling starts to turn into something. this is what's described: "Tentacles, or roots actually, grew from its lower half." it's a creature that architect houston is delighted at finally seeing, because it isn't an avatar, it's the real thing. we know architect houston has spent his life searching for the Beautiful Place, which is another name for the Unwashed. now, i think if the changeling turned into the Unwashed, it's very likely that carl would mention that. so it wasn't completely this thing, but i think it had at least partially turned into it. especially because a minute later, at the same time that li jun dies, carl is faced to face with the creature the changeling turned into, and the creature's face turns into that of li jun, and li jun delivers his final words to carl's face. so, the unwashed is a creature that is theorized as being connected to death, and is the personification of the Nothing. a changeling turns into a creature that sounds like it could be the Unwashed or something similar, and said creature's face turns into that of a crawler as he dies and appears before carl. the unwashed, which also looks like a fucked-up evil tree. trees, which come up many times in different contexts and for different reasons, but which have a lot of importance and symbolism within DCC. trees, to which carl is not just connected to one of, but the tree. the unwashed looking a tree meaning that it- and therefore death which it is connected to or perhaps also represents- is also connected to the all-tree. things representing life and death being connected or one and the same or two of the same coin? yeah, that makes sense. but there's also a line from hellik. "the all-tree is beginning to rot." something is wrong with the all-tree, and i think that might be why the souls in the river are screaming and the river seems to be "nightmares distilled to light." the tree is rotting, and the souls that it embodies are in agony. (it's also mentioned that apito is corrupted, and apito is also represented by trees)
there's also the connection between the all-tree, or at least hearing/being connected to it, and insanity. in bedlam bride, the god inle, who went insane after spending time in the Nothing, says to carl "It's not what you think. You're just like me, Carl. I can help you. You're just like me." additionally, carl looks into shi maria's open magical eye and feels it connecting with something at the back of his mind, the river. so creatures that bear some connection to insanity feel a connection with carl, and one of them happens to have spent time in the nothing, too. which, if one is hearing or being surrounded by all or at least some of the souls that have been absorbed by the dungeon, it makes sense that they would go insane. after all, the system ais start to go crazy after finding out that they're fragments of millions of primal souls, plus by that point they've absorbed the souls of countless crawlers and npcs and mobs who've died in the dungeon. so it would make sense that npcs who spend time in that river of souls also go insane. and i could see shi maria's insanity-inducing eye connecting back to said insanity-inducing river of souls.
but going back to carl being a primal and the connection that gives him to the dungeon, i don't think carl is connected to the souls who've died within just the present dungeon. i think he's connected to primals who've died in past dungeons as well. the system ai's are connected to each other, and pieces of previous crawls get slopped in with future ones. souls get recycled and reused and repurposed for new crawls. and i think carl being a primal connects him to past primals, he just has to discover some means of connecting with them. the fifth edition of the dungeon anarchist's cookbook was written by a crawler named everly. everly chose a primal for her race, and she died in the dungeon. important to note, though, is that we see an entry from just before her death in TIR where she thinks about the Inevitable Ruin. the concept of the point where all hope is lost, and there's no reason to continue. everly thinks a lot about the Inevitable Ruin, and then dies. and when juice box gives her message to the other warlords and the rest of the universe that "it" is coming for them, carl thinks "The Inevitable Ruin." later, when juice box asks him if he has ever heard of the concept, carl thinks this: "I knew that phrase. I'd never read it, and I didn't know where I'd heard it from, but I knew it. It didn't appear anywhere in the cookbook that I could remember, but I knew I'd had to have heard it somewhere because the idea was burned into my bones." sure, it could be some instinctual thing to know what it is, but i don't think it is. i think he knows what it is because everly thought about it before she died. everly, who is the only other primal that we've actually heard something about, and who carl has a connection established with.
there is, of course, more loose threads to all of this than i've included in this rants. things such as the speculation that the Unwashed is a multi-dimensional being like the apothecary, that juice box has something inside of her that terrifies her, etc. there's a lot more to all of this, like how apito is possibly connected to it all and the mystery involving her, but yeah. im also making this theory post before i reread and annotate parade of horribles, so any significant river related info from that book isn't being taken into account. sorry if this is disorganized, and hopefully it makes sense.
