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.
One possible scenario could be that Draco has a change of heart at Malfoy Manor. He might secretly try to protect Hermione from the other Death Eaters. Maybe he uses his knowledge of the manor's secrets to hide her or mislead the others. For example, he could tell them she escaped through a certain passage when in fact he has her hidden in a secret room.
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.
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.
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.
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.
It could be that Ron starts dating another girl in the fanfiction, and Hermione has feelings for him. Seeing him with someone else would be heart - breaking for her and cause her to cry.
One interesting scenario could be them going on a magical adventure outside of Hogwarts during the summer holidays. They might discover a hidden magical creature and have to work together to protect it from dark wizards. Another could be a time - travel adventure where they go back in time to change a small event that has big consequences in their present friendship. And they could also have a friendly competition within the fanfiction, like a wizarding cooking contest where they use magic to create the most amazing dishes.
In some fanfictions, Ron might be under the influence of a spell or some dark magic that changes his behavior. If he starts acting in a way that is harmful or annoying to Hermione, like constantly arguing with her or trying to undermine her work, she could end up hating him. Also, if there's a competition in the fanfic, say for a powerful magical item or a high - ranking position in the wizarding world, and Ron tries to cheat Hermione out of it, that would likely make her hate him.
One common and appropriate scenario is them going on adventures together after the events of the main series. For example, they could be traveling the wizarding world, exploring new magical creatures and spells. This allows for the development of their relationship in a new context while still maintaining the magical and adventurous spirit of the original series.