Perhaps in the fanfiction, Elsa and Jack find a baby lost in the frozen woods. They decide to take care of the baby together, using Elsa's ice powers to create a warm and safe shelter and Jack's ability to bring fun and playfulness to the baby's life. As they care for the baby, they develop a deeper bond between themselves.
In this fanfiction, a magical event causes a baby to be formed out of ice and snowflakes. Elsa is naturally drawn to the baby as it seems to be a part of her ice - based magic. Jack Frost arrives, and they both realize that the baby has the potential to bridge their two very different worlds. They embark on a journey to protect the baby and figure out its true nature.
One idea could be that Elsa discovers she has the power to create a magical baby snow creature, and Jack Frost comes to visit and is fascinated by it. They then start to explore the possibilities of Elsa's powers together in relation to this new creation.
They can develop their relationship through their shared care for the baby. For example, when the baby is sick, Elsa uses her powers to keep it cool while Jack tries to cheer it up. This mutual effort in taking care of the baby can bring them closer.
If we're talking about a fanfiction where Elsa and Jack Frost have a baby, there are so many storylines that could develop. The baby could be a key to uniting different magical realms that are related to winter. It might face challenges growing up, such as being accepted in both Elsa's world and the world where Jack Frost belongs. The baby's powers could also be a source of both wonder and danger. For example, if it couldn't control its powers properly at first, it could accidentally cause blizzards or freeze things in inappropriate places. But with the love and guidance of its parents, it could learn to use its powers for good and become a beloved figure in the winter - themed magical world.
The story could be about the baby's discovery of its powers. It might start with the baby accidentally creating a small snowflake, which then grows into a large snowstorm. Elsa and Jack would then have to teach it how to control this power.
One idea could be that a powerful dark sorcerer kidnaps Elsa because he wants to use her ice powers for his own evil deeds. He locks her in a magically sealed dungeon deep in an ancient castle. Another plot could involve a group of thieves who mistake Elsa for a valuable princess they can ransom. They take her to a hidden lair in the mountains. A third option is that a jealous rival from another kingdom, who envies Elsa's powers and her popularity, arranges the kidnapping to discredit her.
One idea could be that Elsa discovers she has vampire powers after being bitten in a hidden part of the frozen forest. Another could be a love story where a vampire falls for Elsa and tries to convince her to embrace the dark side while she struggles with her own ice powers and the implications of becoming a vampire. Or perhaps Elsa is turned into a vampire and has to learn to control her new thirst while still ruling Arendelle.
A plot idea might be that there is a strange blizzard that is not caused by Elsa. Kristoff, suspecting foul play, comes to Elsa for help. Together, they discover a dark sorcerer is behind it. As they battle the sorcerer, Kristoff helps Elsa see that she doesn't have to be afraid of her powers and can use them more freely. This could lead to a deeper friendship or more between them.
One interesting plot could be that Jack Frost discovers Elsa's baby has the power to control both ice and snow in a unique way. He then decides to mentor the baby in controlling its powers. Another could be that the baby's presence somehow brings a new season to the magical world that combines the best of Jack's winter and Elsa's Arendelle's climate.
One idea could be that Elsa and Anna discover a hidden magical realm within Arendelle. They meet new magical creatures there and have to work together to solve a problem that threatens both this new realm and Arendelle. For example, a dark magic is spreading and only Elsa's ice powers combined with Anna's courage can stop it.
One plot idea could be that Elsa discovers a mysterious stranger from a far - off land who is immune to her ice powers. As they get to know each other, she starts to fall in love. They go on adventures together, exploring new lands and facing challenges that test their relationship.
One idea could be that Elsa and Jack Frost discover they both have the power to control elements in a unique way. They could team up to save a magical world that is being threatened by a dark force that can nullify their powers. Another plot could be that they meet and initially clash because of their different approaches to using their powers, but then gradually learn from each other and fall in love.