One idea could be that Draco and Hermione are forced to work together undercover among the Death Eaters. They start off distrusting each other but as they face various challenges within the Death Eater ranks, they begin to understand each other better. For example, they might have to find a way to stop a particularly heinous Death Eater plan while pretending to be on their side.
A different plot could be that Draco has a change of heart due to Hermione's influence while they are both in the Death Eater world. He starts to question his family's loyalty to Voldemort and together with Hermione, they try to secretly undermine the Death Eaters from within. This could involve them stealing important dark artifacts or passing on information to the Order of the Phoenix.
A possible plot twist could be that Hermione gets turned into a Death Eater against her will, and Draco has to help her break free from the dark magic controlling her. This would completely reverse their typical roles.
One plot idea could be a werewolf Death Eater who is forced to work with Hermione under some strange circumstances. Maybe they are both on a mission to retrieve a powerful magical artifact, and along the way, the werewolf starts to question his loyalty to the Death Eaters as Hermione shows him the value of kindness and justice.
One idea could be Hermione discovers she has a long - lost pureblood heritage that has some ties to the Death Eaters. Maybe her family was involved in some secret Death Eater plot in the past, and she has to uncover the truth to clear her family name.
A more complex plot could involve Hermione being transported back in time to a period when the Death Eaters were more prominent. There, she has to interact with a Death Eater who is different from the others, perhaps more morally ambiguous. They end up influencing each other's views on magic and the wizarding world. This kind of time - travel plot combined with the Hermione - Death Eater dynamic can lead to a very engaging and rare fanfiction.
Well, it could be that Draco is forced to follow the Death Eater path while Hermione is fighting against them. But then, they might get thrown into some situations together, like being trapped in a place. Draco realizes that Hermione is not just a Mudblood in the sense that he was taught, and they start to form an unlikely bond. Their relationship could be full of tension, with Hermione constantly trying to convert Draco or at least make him see the wrong in what he's doing, and Draco struggling between his loyalty to his family's Death Eater ideals and his growing feelings for Hermione.
One idea could be that their child discovers a hidden magic that neither of their parents were aware of. This magic could be a key to solving an ancient mystery in the wizarding world. Another plot could be the child having to navigate the social difficulties of being the offspring of two former rivals, facing prejudice from some pure - blood families who still hold grudges against Hermione for being a Muggle - born.
One plot idea could be that Draco and Hermione are rival CEOs in the wizarding business world. They start off hating each other due to their different management styles and company loyalties. But then, they are forced to work together on a project to save the wizarding economy. As they spend time together, they begin to understand and respect each other, and eventually fall in love. Another idea is that they are co - CEOs of a newly formed, progressive wizarding company that aims to bridge the gap between pure - blood and Muggle - born wizards in the business realm. Along the way, they face opposition from traditionalist wizards but they fight it together and their relationship deepens.
One idea could be that Draco and Hermione's baby has unique magical abilities that draw the attention of both the wizarding world's good and bad elements. The baby might be able to communicate with magical creatures in an extraordinary way, leading to adventures where they have to protect the baby from those who want to use its power for evil.
A possible plot is that Draco, who is in Slytherin, discovers a hidden secret about Hermione's family that has ties to Slytherin. This makes him see her in a new light and they start to form an unlikely alliance. They could then face challenges from their respective houses. Another plot idea is that in an alternate universe, Hermione is sorted into Slytherin and she and Draco become friends and then something more, as they strive to change the negative perception of Slytherin from within.
In a fanfiction plot, there could be a situation where Hermione and Draco are both cursed. The only way to break the curse is to work together and learn to trust each other completely. They have to rely on each other's unique magical abilities. Along the way, they share their deepest secrets and fears, which brings them closer together. By the time they break the curse, their relationship has transformed from one of enmity to something more like friendship, with the potential for more.