THIS IS A SUMMARY OF FROZEN! If you remember it well, you do not need to read this. I tried to make it interesting to read even for someone who knows the story, but I cannot guarantee my success. The biggest reason I did this is because I want to do this for all my stories.
What has gone before:
FROZEN:
In the kingdom of Arendelle, there lived two princesses, Anna and Elsa.
The elder of the two sisters, Elsa, was gifted with awesome magic: control over cold temperatures as well as water in it's cold, solid form.
Anna was ordinary apart from being royalty.
When the princesses were young, they were inseparable. Or so everyone thought.
An accident in the ballroom caused a five year-old Anna's head to be frozen, and while the magic trolls were able to repair the broken mind, there were able to do nothing about the fear that the king, queen, and the eight year-old princess felt about the accident.
To prevent further harm, Princess Elsa was locked away, so that she could do no further harm to anyone until she learned control over her gift.
The gift that was quickly starting to feel like a curse.
Thirteen years later, Elsa, now aged 21, was to be crowned queen. And she was.
The celebration that followed the coronation was cut short by Elsa accidentally revealing her powers to everybody.
Scared, she fled Arendelle, freezing it in the process.
It was the middle of summer.
Anna set out to retrieve her sister, putting Prince Hans of the Southern Isles, a man she had just met, and gotten engaged to, that day, in charge of Arendelle in her absence.
Anna found aid in the form of Kristoff, an ice harvester who needed summer back to make a profit; Sven, Kristoff's reindeer companion who often served as his conscience; and Olaf, a living snowman Elsa built alongside an ice palace after she ran from the kingdom.
When Anna got to her sister's newly-built castle, Elsa refused to go back with Anna and accidentally froze her heart. She also crafted a giant snow creature called, "Marshmallow" to make sure they didn't return.
Anna, Kristoff, Olaf, and Sven all set out to unfreeze Anna's heart while Hans went to the North Mountain, where Elsa's palace resided, to find Anna.
Instead he found traitors among them who wished to murder Elsa to stop the winter. Elsa quickly overpowered the two men before Hans could even enter the castle, and Hans pleaded with Elsa to spare them.
He noticed one of the men readying his crossbow and changed the trajectory of the shot to puncture the support to a massive chandelier above Elsa rather than Elsa herself. Nonetheless, the chandelier fell, and Elsa had just enough time to jump out of its way before it crashed down were she used to be standing.
She blacked out.
When the other party arrived at their destination, they found that only an act of true love could thaw Anna's frozen heart, so they set out to kiss Hans, but who is this Hans, truly? Anna doesn't know anything about him, but she "loves" him...?
When Elsa regained consciousness she saw she was in Arendelle's dungeon. Hans entered to beg her to unfreeze everything. She said that she can't and, instead, begged to be let go.
Anna returned to Arendelle to kiss Hans, but he revealed that he was working from self-interest the whole time, wanting the throne of Arendelle for himself.
Thinking Anna is as good as dead, Hans departed to the dungeon to "avenge" his fiance's death and ascend to the throne, but both Elsa and Anna escaped the rooms they were locked in. Elsa wanted to escape, but Anna wanted to reach Kristoff to kiss him to save herself. Eventually, Hans caught up to Elsa and was about to kill her when Anna got in the way, freezing to solid ice milliseconds before the sword touched her. The sword shattered and Anna's sacrifice for her sister thawed her heart. Kristoff and Anna started dating after that.
It's been nearly a year after that experience, but Elsa is still having nightmares about it. Hopefully Anna can help.