I really enjoyed episode 1, brought back a lot of the feelings from season 1. The setting of Alaska once it goes dark is really smart, it just makes everything feel more claustrophobic and ominous.
I know this isn't high-level analysis but feels like the killings are going to be associated with someone high up with the mining operation, or the town itself. Annie protesting makes that conclusion easy to draw. Also the scientists are researching climate change, easy to draw that conclusion as well.
One thing I looked up is Annie's middle name, Masu, is Japanese for less than, it's an insult so they're implying she, and I'm guessing the rest of the native population, are looked down upon by the white people. I hope I'm wrong on that, not because of the drawing of any political conclusions, because if it's that easy it's just lazy writing. If the entire town exists due to the mine it's also possible the locals would want to silence her because that's where all the town's resources come from.
A common theme of the first three seasons is the subjugation and abuse by the powerful upon the weak, people that are barely seen as existing. They go after people that aren't going to be missed, a person with the middle name meaning as much seems a little on the nose to me, but like I said I hope I'm just falling for misdirection. Maybe it's a giant conspiracy between the mine, the town, and the police force. Did they ever really explain why Hank would hold onto that file? The circumstances around Annie's death and the scientists are very different though.
PS if you're enjoying this I recommend watching The Head, also on MAX. Another murder mystery set in the arctic. Or the first season of Fortitude which I think is on Amazon, second season was a little off the rails.