Well, imagine Hermione has been hit by a strange potion that makes her regress to a child - like state where she's weak, helpless, and afraid. Draco, who has been assigned to look after her (for some strange reason by the school authorities perhaps), finds himself in an awkward situation. At first, he's frustrated with the task, but as he spends time with her, he starts to see her innocence and vulnerability in a new light. He might start to teach her basic things again like how to use a wand (in a simple way), and this could lead to a really heart - warming story of their growing connection.
A simple idea could be that Hermione is in a cursed forest where all her knowledge is useless, and she's weak and afraid. Draco enters the forest for some other reason and finds her. He decides to help her get out, and during their journey, they start to understand each other better. It could be a story of how they overcome their differences.