Perhaps they are there to rescue someone. Hermione might come up with a clever plan involving potions and charms to get past the manor's defenses. Ron, with his loyalty and determination, would be right by her side, ready to take on any danger that comes their way.
In some fanfictions, Ron and Hermione could be at Malfoy Manor for a diplomatic mission of sorts. The wizarding world is in chaos, and they are sent to try and convince the Malfoys to switch sides. This would be a very difficult task as the Malfoys have long been associated with the dark side. But Ron's loyalty and Hermione's persuasion skills could potentially make a difference.
It could also be a result of a magical bargain or curse gone wrong for the Malfoys. Suppose there was a powerful dark magic object in the manor that got out of control. Hermione, with her vast knowledge of magic, manages to contain it. In the process, she ends up being the rightful owner according to some ancient magic laws. This would make for an interesting plot twist in the fanfiction.
Well, one scenario could be that they are attending a peace - making event. Hermione, being the diplomat, tries to make amends between the Weasleys and the Malfoys, and Ron is there just to support her and make sure she doesn't get into any trouble. But things quickly go awry as old rivalries resurface.
A common plot is that they are sneaking into the manor to steal something important, like a magical artifact. Ron would be on the lookout for any danger while Hermione figures out how to bypass the manor's defenses.
After Malfoy Manor, their relationship could also become more public within the wizarding community in fanfiction. They may face different reactions from friends and family. Some might be overjoyed seeing them finally together, while others might be a bit skeptical. But through all this, Ron and Hermione would grow closer, learning to deal with external pressures as a couple, and also finding new ways to support each other in the fight against the Dark Arts.
Ron could become more confident in his relationship with Hermione. After seeing her in such a dangerous situation at Malfoy Manor, he realizes how much she means to him and is more assertive about his feelings. He might also grow in his magical abilities as he wants to be better able to protect her.
One possibility could be a very sweet and romantic evening. They might have a private dinner together, reminiscing about their journey from friends to lovers. Then, they could slow - dance in their room, just enjoying each other's company and the fact that they are finally married.
Well, perhaps they would get involved in the rebuilding of Hogwarts. Ron could use his strategic skills and Hermione her vast knowledge to help make Hogwarts better than ever. They might also start teaching there, passing on their knowledge and experiences to the younger students.
In this fanfiction scenario, Ron could draw on his knowledge of the wizarding world. He might remember some ancient spells or potions that could safeguard Hermione. He'd be really determined to protect her. He could also call on his friends like Harry for help if the situation got really tough.
Another possibility is that it could focus on their adventures together. They might go on some sort of mission or exploration within the wizarding world. It could be related to a new threat that has emerged, and they have to use their combined skills and knowledge to deal with it.