The movie focuses on a younger Fjellrose, back when she was just a princess, who has never set foot outside of Blåfjell and is not very brave. However, when her father gets ill, she must seek advice from the elders on how to save him, leading her to travel to the village where the humans and rødnisser live, where she meets a rødnisse boy named Dreng. However, when her actions put both blånisser and rødnisser in danger, she must try to set things right with Dreng's help.
Later got a sequel, Blåfjell 2: Jakten på det magiske horn. An unusually cold winter puts the farm Dreng and the other rødnissene live on in danger. Fjellrose decides to look for the magical horn, which has long been missing and can manipulate the weather, in hopes of saving the farm.
- Anti-Villain: The farmer who drives rødnissene out of their home in the first movie isn't a bad person, he's just really frustrated because someone keeps stealing his things, correctly assuming nisser to be responsible.
- Awesome Moment of Crowning: Fjellrose receives her crown and becomes queen at the end of the first movie.
- Big Damn Movie: Both movies, to some extent:
- In Jul I Blåfjell, the main conflicts revolved around people dumping trash near the mountain and having to figure out how to deal with the situation of one of the oldest blånissene having broken an ancient rule by having brought a rødnisse into the mountain. In Jul I Månetoppen the main conflict revolves around whether it is blånissene or rødnissene have the rights to the blue berries on a certain mountain top, with both having good reasons for needing them. In this movie? The climax of the movie has the whole world in danger of falling into eternal night.
- The second movie feels closer to the series' it is based off of in tone, although the stakes are still higher than usual, involving a magical horn that can change the weather.
- Cassandra Truth: The one farmer in the first movie who (correctly) believes that nisser are the ones responsible for stealing his things can't seem to get any other humans to take him seriously.
- Cool Old Lady: Mosetussen that Fjellrose and Dreng befriend in the second movie, who helps guide them through her old home which has been taken over by humans and several times saves them from being spotted by the humans while they try to retrieve the magical horn.
- Darker and Edgier: The first film has a much more serious tone than the series it was based off of. In the series, blånissene were simply said to be around to protect the mountain, but in this movie, they add a detail that they are needed to stay in the mountain to maintain the flow of time. At the climax of the movie, the world nearly ends up falling into an eternal night, which would eventually mean the death of every living thing. And while we know from the rules established in Amalies Jul and Jul I Blåfjell that rødnisser will disappear if a human sees them, and blånisser will disappear if they don't make it back into the mountain before the blåtimen is over, this movie is the first time both of these things happens on-screen.
- Darkest Hour: In the first movie, the blue silver is taken away from Blåfjell by the farmer who had driven rødnissene away from their home, meaning that the world will fall into eternal night and all living things will eventually die, and blånissene blame Fjellrose for all the problems caused by her attempt to get the money she thought could cure her father, and her father has no choice but to banish her for breaking their rules.
- Distracted from Death: When rødnissene are about to head home, Fjellrose's father tells her to go say good-bye to them. By the time she returns to her father's chamber, he's already passed on, and after Fjellrose's coronation see that he's joined the other ancients.
- Foregone Conclusion: Considering Fjellrose is the blånisse queen in both Jul I Blåfjell and Jul På Månetoppen which this movie is supposedly a prequel to, it's pretty obvious that Princess Fjellrose wouldn't really end up being banished from Blåfjell forever by the end of the movie. Same goes for the second movie, where we know that Fjellrose giving up her position as queen wouldn't be permanent.
- Vom's fatal flaw. He was the one responsible for stealing the farmer's things.
- The villain of the sequel is also motivated by greed, wanting to mine coal to make money, and using the weather altering horn to make the weather colder.
- Karmic Death: Vom ends up being spotted by a human and disappearing because he tried to gather up all the things he'd stolen after Fjellrose and Dreng returned them to the farmer's house.
- Kid Has a Point: In the sequel, while the older blånisser are reluctant to tell Fjellrose about the magical horn because of how dangerous it's weather manipulating power can be, she's also being encouraged to listen to her heart, and she believes the horn can be used to save the village Dreng and the other rødnissene live in from being crushed by the glacier that's threatening to destroy it. As it turns out, the main villain of the movie has found the horn, and is the one responsible for the unusally cold weather, and thus things would likely have only continued to get worse had Fjellrose not decided to try to retrieve it.
- Nice Job Breaking It, Hero!:
- Fjellrose steals a single coin from a farmer, which ends up driving rødnissene out of their home because someone had already been stealing a lot of things from that particular farmer, with the coin being the last straw. She also mentions the blue silver, when Dreng suggests that they give the farmer something he'll like so that rødnissene can return home, leading to Vom convincing the other rødnissene to take it out of the mountain, thus nearly dooming the world to an eternal night.
- The reason the above happens is because one of the ancients Fjellrose asked for advice recalled an incident from his childhood, when he overheard a human talk about how they could've saved someone who was sick if only they had had money. However, said ancient never actually learned was money was, and assumed it was something magical that could heal those who were sick. This is what gives Fjellrose the idea that money might have the power to save her father, leading her to set out on her quest.
- In the sequel, when the other blånisser tell her about the magical horn that can change the weather, they are clearly concerned something like this might happen again. However, Fjellrose has learned from the previous movie. Her friend Dreng on the other hand, ends up getting impatient and refuses to wait for the next Blåtime for Fjellrose to get rid of the glacier that's threatening to destroy the village they live in. He takes it from her and blows in it twice, causing spring to come prematurely, and partially flooding the inside of Blåfjell as the snow melts much too fast, even if it did solve the glacier problem. He also ends up letting the magical horn fall right back into the villain's hands, albeit he did so in order to save Fjellrose and the rødnissene who were about to be found by the villains. Naturally, the main villain ends up blowing in the horn three times to make it colder, summoning the storm that blånissene had accidentally summoned in the past and which Fjellrose had been warned about.
- No Body Left Behind: Happens to one of the blånissene in the opening narration, after being too distracted admiring the first blåtimen and thus disappears after not making it back into the mountain before blåtimen was over. This also happens to Vom near the end, when he is spotted by a human while trying to gather up the things he'd stolen after Fjellrose and Dreng had returned them to the farmer's house.
- No Man Should Have This Power: After stopping the blue storm and bringing the magical horn back to Blåfjell, Fjellrose decides that the magical horn should be destroyed, reasoning that the weather can do fine on it's own and that one shouldn't try to control it.
- Rollercoaster Mine: The magical horn ends up falling onto a mine cart which starts rolling away, leading to Fjellrose and Dreng having to follow it in another mine cart during the climax of the sequel.
- Rule of Three: If the weather altering horn is blown into three times in succession, it'll summon a powerful storm which caused a lot of problems in the past. The main villain ends up accidentally doing just that in the climax of the movie in order to quickly make the weather cold again to sell more coal.
- Running Gag: Some of the coal miners in the sequel believe the mine to be haunted (partially due to the antics of Fjellrose, Dreng and Mosetussen while they're looking for the horn), and keep reacting to various items they see moving by screaming "X (the item in question) ghost!"
- The Night That Never Ends: Nearly happens at the climax of the first movie, when rødnissene steal all the blue silver in order to get the farmer to leave them alone. Luckily, Fjellrose and Dreng are able to set things right by retrieving the blue silver and returning the items that Vom stole from the farmer in exchange.
- Villain Song: The villain of the sequel has one which is also a Crowd Song where he and the coal miners sing about how they work to gather the coal so he can make money.