Let’s start with visuals. It’s very striking visually, majestic even. The volcano under the glacier near the village is erupting, you see, so everything is coated in ash, and there are huge clouds looming up on the horizon, and ash storms when the wind is from that direction, and so forth. And nearly everybody has left. There are also some fairly impressive visits down into a crevasse in the glacier, and into a tunnel down there, where lava is flowing near to the water (maybe unrealistically? at least I wouldn’t want to be near enough to see it in person!).
Mysterious things start happening. Like, people thought to be dead (and soon, people known to be dead) start walking off of the glacier covered with volcanic debris. These people seem to remember everything they should remember (but not a lot more), but we never quite get to a DNA test (the DNA test is run on the body of the actual Asa, not on the changeling who walks off the glacier).
Oh, did I say “changeling”? That’s what the old woman who runs the hotel mentions, anyway. Apparently weird people showed up when that volcano was erupting long ago, too, and may be the source of the whole legend of elves or changelings or little people or whatever.
Everybody is of course severely low-affect, and at least sub-clinically depressed. They all seem to have had lives full of pain and trouble, too. The one who spends time in the church, prays, and has a cross hanging from his rear-view mirror goes solidly off the rails and tries to use God to justify dirty work, too; I always like that (he’s also the policeman).
Eventually one of the geologists finds something that he thinks is pieces of a meteor, from under the glacier, and that the weird effects are caused by that. That makes it, I guess, an SF movie, at least at the very bad 50s level. Because, while visually it’s excellent and the characters are complex and fairly interesting, the science does not bear thinking about; it’s offered as an excuse for the psychological torture the characters are put through, nothing more.
So, eventually we’ve got a clone of a woman there 20 years ago working in the hotel, Asa, her clone, and her dead sister, the geologist’s dead psychopathic son Mikael, a healthy clone of the dying wife of the policeman. And an army walking off the glacier at the end; dunno if they’re planning a second season or if that really is the end.
By the end we have two clones committing suicide (and two originals), one murdered, and some near escapes. We have two clones taking over the position of their originals. Not a bright fluffy bunny sort of a series. I think this is shown as being a relatively good outcome for the people surviving.
There is a content-warning for suicide. The very last episode also has a big warning at the front about a suicide scene (which deserves a warning). But what they do not warn you about is the scene where the mother drives away from her 6-year-old son in the wilderness (when she realizes that he cannot possibly actually be her son, despite his appearance and memories, he’s the wrong age; plus that he’s dangerous), nor the scene where the child slashes the throat of one of the good Samaritans trying to rescue him, nor the scene where his parents walk him out into the ocean and drown him.
The warning for smoking, of which there is very little, seems really banal at that level.
So. I am not recommending this in any broad way. It’s grim (but I chose to watch my way through it, and I generally hate grim), violent, full of depressed people, and rather wrenching. As SF it’s very thin; you have to watch it as mystic mainstream or something instead. But it’s very well done in many ways, so if those things appeal to you it’s worth a try.