Perhaps a plot where they all become animagi and have to use their animal forms to solve a mystery in the Forbidden Forest. Draco as a sleek snake, Harry as a stag, and Hermione as an otter, they must navigate the forest's dangers and uncover the truth about a strange magical disturbance.
One interesting plotline could be that Harry, Hermione and Draco discover they are all descendants of Peverell in a way that forces them to work together. They might have to combine their unique magical abilities, with Harry's courage, Hermione's intelligence and Draco's knowledge of the Dark Arts (in a non - evil way). This could lead to them uncovering secrets about the Peverell family that were long lost and that have great significance for the wizarding world.
One interesting plotline could be them working together to solve a mystery within Hogwarts that the regular faculty can't handle. They combine their unique skills - Harry's courage and leadership, Hermione's intelligence and Draco's knowledge of the Slytherin side of things. For example, they might be on a quest to find a hidden magical artifact that has been causing strange occurrences in the school. This forces them to put aside their differences and really function as a pack.
One interesting plotline could be them growing up together and having to hide their relationship from the wizarding world because of the implications it would have on the existing power dynamics. Another could be them using their combined skills, Hermione's intelligence, Harry's courage, and Draco's knowledge of the pure - blood society, to fight a new dark force in the wizarding world.
One possible plotline could be Draco and Hermione being forced to work together on a difficult school project. Despite their initial animosity, they gradually come to respect each other's intelligence and skills. Another could be a situation where they are both in danger and have to rely on each other for survival. This forces them to set aside their differences. And a third could be a magical accident that causes them to swap personalities or abilities, leading to some humorous and also relationship - building moments.
Well, perhaps there's a plot where they are both entered into a magical tournament against their will. In the process of competing, they realize they have more in common than they thought. For example, they both have a strong desire to prove themselves. This shared feeling makes them bond and slowly become friends, or even more, in the fanfiction world.
One interesting plotline could be that Draco and Hermione are forced to work together in a cancer research project at Hogwarts. They start off hating each other as always, but as they see the effects of cancer on patients, they gradually put aside their differences. Hermione's vast knowledge of magic and Draco's family's connections to certain potions ingredients could lead to them making a significant discovery in the fight against cancer in the wizarding world.
One interesting plotline could be Hermione trying to cure a werewolf - affected Draco. Maybe she discovers a new spell or potion that can ease his lycanthropy symptoms. It could lead to a lot of tense moments as they have to trust each other despite their past differences.
One possible plotline could be that Draco, in his 'evil' guise, is initially set on causing trouble for Hermione at Hogwarts. But as the story progresses, he might start to have complex feelings for her, leading to an internal struggle between his dark intentions and new - found emotions.
Some fanfictions explore a different relationship dynamic between them. Maybe Harry has a problem that only Hermione can understand and help him with, and this brings them closer in a way that's different from their normal friendship. It could be something related to his connection with Voldemort or his family history.
One possible plotline could be that they are forced to work together on a difficult project in Hogwarts, and during the process, they start to see each other in a new light and eventually share a kiss. Another could be in a post - war scenario where they have to put aside their previous differences for the greater good of the wizarding world, and feelings develop leading to that kiss. Maybe in an alternate universe where the Gryffindor - Slytherin rivalry doesn't exist in the same way, they meet under different circumstances and fall for each other, which results in the kiss.