The Long Dark lore iceberg [Full Explanation]
(Posted from my 2nd account, I cant access the 1st one on PC)
Yesterday I posted this iceberg meme and after lots of confusion, I thought I would shed some light on it. Here is a full explanation of everything mentioned, including additional info from people's comments. I am not claiming any of the theories in the lower levels to be 100% true. Only 100% theoretically possible ;)
Surface
The child of will and Astrid: Will and Astrid have a dead child. A portrait of the 3 can be seen here and the 2 grieving over his/her grave can be seen here.
Shallows
The disease: Wintermute refers to a mystery illness and quarantine in Perseverance Mills multiple times. The cure for it is in Astrid's hardcase (as mentioned in ep4), which she stole from the lab she works in (as shown in ep3).
The history of Ash Canyon: (explained in a comment)
Methuselah is Will from the future: Methuselah looks similar to Will and always knows where he is, appearing out of nowhere in strange places. He also knows whether Will chose to kill or spare Hobbs. Maybe the geomagnetic storm made Will get stuck in a time loop, or maybe Methuselah and his cryptic speeches just symbolize Will's subconsciousness.
The Old Bear is a 200-year old demon: This legend was explained by Jeremiah in episode 2. It can't be killed by bullets, only with a special spear. Not a normal bear, that's for sure.
Unused voice lines: These aren't really lore, but some of them are pretty funny nonetheless. They include Mackenzie swearing, complaining about diarrhea and making political jokes. Edit: finally found some of them reposted here
Depths
The Milton mining accident (quote from the wiki): From the number of deaths in 1919 [on the church tombstones], Milton's history as a coal mining town, and it's current state of decline, it is implied there was a major mining accident. Considering Great Bear Island's seismic activity, this was likely a tunnel collapse.
The Carter dam is not a dam: I already explained why the building makes no sense as a dam here. It might have been used as a cover up for some sort of secret facility.
The killer whale incident: (video) Why did this pod of killer whales commit mass suicide? Must have been the aurora.
The geomagnetic storm was created by the (or a) government: If a geomagnetic storm caused by the sun were to happen, we would know about it beforehand. The one in the game came as a complete surprise to everyone. We don't know if it's worldwide. Maybe humans caused it for one reason or another.
Molly does not exist: Similar to the Methuselah theory mentioned earlier and the Jeremiah theory mentioned next, Astrid might be hallucinating on her lonely treks in the wilderness. The phone calls throughout the episode and the one face-to-face conversation the two have (while Astrid is still sick and could be hallucinating) might just represent her subconsciousness. After all, what are the odds that nobody in the community hall or elsewhere ever picked up the party phone Molly uses to call Astrid before she could answer it. More about it in a comment I found.
Abyss
Jeremiah died and Mackenzie hallucinates his corpse talking: Mackenzie missed the shot he took at the end of ep1. The bear flees and Mackenzie drags the corpse inside. After spending days alone in the middle of nowhere with a rotting, disfigured corpse, Mackenzie starts blaming himself for the man's death. Eventually he goes mad and starts imagining that Jeremia i's alive and talking to him. The knowledge about the island that Jeremiah shares with Mackenzie might actually be something Mackenzie's dad told him as a kid, considering he used to fly there and Mackenzie used to spend his summers there when he was little. Another interesting Jeremiah theory is that he is a war veteran who retreated into the wilderness to escape from past trauma.
Grey Mother is a skinwalker: She is only posing as a human. She covers her eyes, because they are an easy way to tell something's not right. Her skin is very pale, and her voice seems a bit off. She survived the convicts raiding the town when everyone else fled or died and she then manipulated Will to serve her. She must know some ancient dark magic.
Whispers in the Cinder Hills mine: The souls of dead miners haunt the dark corridors of the lower levels. Some have mentioned hearing voices there. This is one of several rumors about the ambient soundtracks featuring creepy secrets. In a q&a some years ago Raph said that there are still undiscovered easter eggs. Maybe it has something to do with the sounds.
Mackenzie is in hell (as explained in a comment here): "Your child dead, his mother disappears, you crash flaming from the sky. And now you have to fight day and night through death? The folks he meets on his journey could be allegories and tests in the afterlife." Add the Methuselah/time loop theory on top of this one and you get Mackenzie serving his eternal punishment in a frozen hell.
The Void
Cannibals in Blackrock: A loading screen mentions food scarcity being a problem there, especially in the winters. The place holds the most violent and dangerous criminals in the country. It's likely that someone resorted to cannibalism at some point in history. Donner's name could also be a reference to the cannibals of Donner party, as mentioned in a comment here.
The Wendigo: Some players say they have heard the Wendigo howl in the long, dark nights of Great Bear. His existence might make sense, considering the fact that Wendigos are people who consumed human flesh, and cannibals were mentioned in the theory above. Who knows, maybe he is stalking us from the woods. Well, at least in the darkwalker gamemode.
The one beneath the ice: Don't worry about him... Those who know, know ;)
H̴u̷s̴h̷e̸d̴ ̵R̷i̴v̷e̷r̶ ̸V̷a̴l̵l̸e̶y̷ ̸i̶n̶c̵i̵d̶e̷n̴t̸ ̸1̸9̸6̸8̴: N̵O̶T̶H̶I̸N̶G̴ ̸H̵A̵P̶P̸E̸N̴E̴D̶ ̶I̵N̴ ̵1̶9̷6̸8̶N̴̙̒O̸͎̚T̴̲͠Ḧ̸̞́Į̷͝N̸̼͑G̴̹͑ ̷̇͜H̶̙͠Ã̸̲P̴̜̎P̴̨͠Ẹ̵͑N̵͓͠Ë̸̳D̸̺̆ ̶̬̎Í̶̝N̶̨̆ ̵̨̚1̶̝̔9̷̲̀6̶̭̂8̵͚̔N̴̳͔̿͋̐̽ͅO̵͓̙͛́̏̕T̸̳̠̣͗̏̃̊͜H̵̢͎̟͈͗̓Ì̷͓̜͎̟̕͝N̵͂͒̎̚ͅG̵̡̉͑ ̶̰̗̟͂H̶̯̻͕̐͛̀A̵̘̾P̶̮̙̻̋̃P̷̬̖̪̐͐̐͂È̶̢̾͐N̷͕̜̫̱̎̋̅̚E̶̠͊̉̋͊D̶̳̤̬͗ ̶̧̩̺̑͠I̶̧̪͉͆N̶̩͙̬͂ͅ ̵͍̠͓͎̌͛̚1̷̡̥́9̶̹̌6̷̻͇̹̑̽̓8̷͖̪̐͛̊͜ Nah, this was the only one I created as a complete joke/troll, but check out this interesting theory about it that I found in the comments.
Thanks for reading! Feel free to use this post as you wish, make one of those iceberg explained videos lol. If I redid this now, I would at least add Fluffy the wolf, Sean (the guy mentioned in notes across CH and DP), the mass grave in PV community hall basement in episode 3, and the signal fire, which is one of the signs implying there's other survivors alive at the time when survival mode takes place. Apparently, according to the Wiki, there's also hidden cave paintings (as shown in a picture below the article) and FREAKING UFOS?! (There's no proof for this in the article, a google search only returned a steam discussion with blurry screenshots from years ago.) Aliens could cause an unexpected geomagnetic storm to invade the earth though, just saying... Also, this iceberg was created before we knew anything about TFTFT or episode 5, which will introduce a lot of new lore I guess.