Perhaps the son from the future discovers that there is a dark force that is going to use the old grudges between the Malfoys and the Weasleys/Hermione to start a new wizarding war. He has to find a way to make his parents see past their differences and unite the wizarding community. His presence in the past might also cause some unexpected magical anomalies, and he has to figure out how to fix them while also achieving his main goal.
Well, one possible plot could be that their son travels back in time to prevent a great disaster that threatens the wizarding world. Maybe he has some special powers inherited from both Draco and Hermione that are crucial in averting this catastrophe. He might face challenges in getting his parents to believe him and work together, as they come from different backgrounds and had a somewhat antagonistic relationship in the past.
The plot could involve their son coming from a future where the wizarding world has become a very different place. He might be on a mission to ensure that his parents fall in love and have him. He could be trying to correct some wrong turns in history that could lead to the downfall of the magical society. He might have to deal with the prejudices of the current time towards his Slytherin - Gryffindor heritage.
He could be very intelligent like Hermione. He might have a sharp mind for magic and academics. Also, he could inherit Draco's sense of pride and self - assurance. Maybe he's a bit of a loner at first because he feels different from the people of the past, but as he gets more involved in the story, he becomes more sociable.
Perhaps their child would be a key figure in bringing about more positive relations between the wizarding world and the Muggle world. Given Hermione's Muggle - born background and Draco's pure - blood status, the child could use their unique position to advocate for better understanding and cooperation. They might even start a new organization at Hogwarts dedicated to this cause, which would be an exciting plot point in the fanfiction.
Maybe the plot could revolve around Lizzie's magical abilities. She could inherit unique magical skills from both Hermione and Draco. For example, she might have Hermione's brilliant academic approach to magic but also Draco's natural aptitude for some darker arts (not in an evil way, but in a more complex understanding). This could lead to her getting into trouble with the school authorities as they misunderstand her intentions. And she has to prove that she's using her abilities for good, perhaps by solving a mystery that threatens Hogwarts.
One possible plot could be that their daughter is a young witch growing up in a world that still has remnants of the old wizarding world rivalries. She could struggle with being the daughter of two former enemies, facing prejudice from some in the wizarding community. She might have extraordinary magical abilities that draw both positive and negative attention, and she has to learn to navigate her own identity while also trying to bridge the gap between the Gryffindor and Slytherin legacies her parents represent.
Well, their son could be highly intelligent like both his parents. He might inherit Hermione's love for learning and Draco's cunning in a more positive way, perhaps using his smarts to solve complex problems at Hogwarts. He could also be a bit of a loner at times, as both Draco and Hermione had moments when they were on their own in their school days. But overall, he'd probably be a very determined individual, not afraid to stand up for what he believes in.
Perhaps the child is on a quest to bring back a lost magic that was present in the past but will be crucial for the future. Fred and Hermione are initially skeptical but as they see the child's abilities and the evidence of the disappearing magic, they start to believe. Together, they embark on a journey to find ancient spells and artifacts that can restore the magic, all while dealing with the challenges of time travel and the secrets the child holds.
In a fanfiction, they could be living together in a secret location. Hermione is on a mission to research a very rare and dangerous form of magic, and Draco has some knowledge about it from his family's library. They form an uneasy alliance. As they live together, they find that they have to rely on each other more than they thought. Draco helps Hermione with the more Slytherin - like aspects of their research, like secrecy and cunning, while Hermione teaches Draco about the importance of kindness and justice. Their living situation becomes a catalyst for personal growth and a potential romantic relationship.
One possible plot could be that Draco, for some reason, becomes Hermione's servant. Maybe it's part of a magical pact or a punishment from the wizarding world. Draco, being used to his pure - blood superiority, would initially resist but gradually learn to respect Hermione's intelligence and kindness. They could then go on adventures together, facing various magical threats and learning more about each other's true natures.
The plot could start with Draco and Hermione realizing their mutual attraction despite their initial animosity. They might secretly plan their elopement to avoid the scrutiny and opposition from their friends and families. Maybe they find a magical place, like an ancient forest where they exchange their vows in a private ceremony.
A possible plot could be that Hermione is getting ready for a big wizarding event and her bra has some sort of magical enchantment on it. Draco accidentally discovers this when he's snooping around (he's still a bit of a troublemaker in this scenario). This discovery leads to a series of events where they have to work together to figure out who enchanted the bra and why. It could be part of a larger plot to embarrass Hermione or to gain some sort of magical advantage.