Sidequest: Aurora Hatch
You unlock this quest by finding the note in the Hunting Lodge cache (Broken Railroad region) so check the “Mystery Lake Supply Caches” sidequest for more information. The note indicates that there’s a secret bunker in the Forlorn Muskeg region, although it’s only acessible during an aurora.
Well back we go. The bunker is located near the north radio tower. There are a few ways to get there, but I prefer approaching from Hat Creek.
Once you get to the tower, turn so that your back is to the railroad, and head to the rocks that are a little to the right. The bunker hatch is hidden behind them.
Will has to wait for an aurora to gain access to the bunker so you’re just going to have to wait for a bit. Auroras can happen anytime during the night if the weather is clear. To ensure you don’t miss it, you want to sleep in one hour increments during the night. There’s a cave near Hat Creek (where my player maker is) if you need somewhere warm to wait, but you’ll have to risk aurora wolves on the way back to the bunker.
Another tactic is to save before sundown and see if an aurora happens that night. If it doesn’t, reload your save and try again. Weather is randomized in The Long Dark, so you may get aurora weather on a reloaded attempt. My only other recommendation is to trying doing this quest during Chapter 4: Renewed Hope. The chances of an aurora are slightly increased during this chapter since it’s required to progress in the story.
Everything after this point is based on the original version of story mode! Take with a grain of salt!
Once the aurora is in the sky, head inside. You’ll see some live wires in the hallway of the bunker. Unfortunately, the letters are in that other room. Now, there are two ways you can go about this. If you’re a cautious player, just sleep until morning since the wires will stop sparking once the aurora is gone. But if you’re impatient or incredibly bullheaded, you can try and tank it through the electrical burns. You’ll end up with very little condition left, but it is possible. Don’t worry if Will dies, because he’ll respawn from the point where you entered the bunker. And once you get past them the first time, there’s a power box on the wall that will let you turn off the wires (don’t worry about getting stuck; that box doesn’t connect to the hatch door).
Jeremiah’s letters are on the metal table. There are also some nice goodies inside (snow pants!) so feel free to loot the place. I think you can even get a bearskin coat if you brought a prybar.
But you do need an aurora to get out. If you tanked it, I would recommend turning off the wires and getting out that same night. Otherwise, you’ll have to wait for another aurora night. At this point, you want to practice rationing. Don’t eat unless you’re going to sleep for 8-10 hours, and make sure to fill your thirst meter with sodas and condensed milk before going for the water. As when you were trying to get in the bunker, make sure to sleep for only an hour at a time.
After you finally get it, it’s time to burn the letters. Will is such a good guy that we don’t even get the choice to read the letters so that’s the only thing we can do. You want to start a fire, but make sure not to use the letters as the starting fuel. It seems this has caused the mission to bug out in some players’ games. After the fire is lit, just go to the fuel section and choose the letters. This cannot be done in Jeremiah’s magic fire since you don’t have access to the fuel page for it.