One possible plot could be that the other characters, like Harry and Ron, immediately start a rescue mission. They might search for clues about where Dolohov has taken Hermione. Maybe they discover that Dolohov is working for a more powerful dark wizard who wants Hermione for her knowledge of magic. Then they have to face various traps and dark spells to reach her.
One possible plot twist could be that Hermione uses her intelligence to outwit Dolohov even while kidnapped. Maybe she manages to leave hidden clues for her friends to find her. Another could be that Dolohov has an ulterior motive other than harming her, like using her as a bargaining chip in the wizarding war. Or perhaps Hermione discovers a hidden power within herself during the time of her captivity that helps her escape.
In a 'hermione meets dolohov fanfiction', perhaps Dolohov is captured by the Order of the Phoenix. Hermione is assigned to interrogate him. At first, they are hostile towards each other. But as they interact more, they start to understand each other's motives a bit better. Dolohov might even start to have second thoughts about his allegiance to the Dark Lord because of Hermione's strong beliefs.
Hermione would likely react with her usual intelligence and quick - thinking. She might start by trying to analyze Dolohov's motives and weaknesses. She could also try to find a way to communicate with the outside world, perhaps using magic in a very discreet way.
Hermione may first try to use magic to defend herself or escape right when the kidnapping is taking place. But if that fails, she will start to analyze the situation. She would think about what she knows of Dolohov from her studies and any previous encounters. Then, she would form a plan. She might even try to find allies within Dolohov's ranks if there are any who could be swayed, by appealing to their sense of self - preservation or better nature.
One possible plot could be that Hermione is on a mission to bring Dolohov to justice for his crimes during the wizarding war. She uses her intelligence and magic skills to follow his trail.
One possible plot could be that Rabastian has some dark motives related to Hermione's magic abilities. Maybe he wants to use her knowledge of spells and potions for his own evil schemes. He could hold her in a secret location, and Hermione would have to use her wits to try and escape or send out some sort of magical signal for help.
One possible plot for this fanfiction is that Hermione wants revenge on the Death Eaters who have caused harm to her friends and the wizarding world in general. Dolohov, having once been a Death Eater himself, could provide crucial information about their hideouts, plans, and weaknesses. This would give Hermione an edge in her quest for revenge. He could also use his combat skills, which are no doubt formidable, to protect Hermione during her confrontations with the bad guys.
It could also be that Dolohov's desire for Hermione causes a rift among the Death Eaters. Some might see it as a distraction or a sign of weakness. This internal conflict within the Death Eaters could then be exploited by Hermione and her allies to their advantage in the fight against the dark side.
One possible plot could be that in an alternate universe, Dolohov has a change of heart. He somehow crosses paths with Hermione, and they gradually develop an unexpected bond. Eventually, they have a child, and the story could revolve around how they protect their family from the prejudices of both their former worlds.
A possible plot for Hermione and Dolohov fanfiction could be that Hermione is researching a very rare and dangerous form of magic. Dolohov, who has some knowledge about it, crosses her path. At first, they are at odds, but as they dig deeper into the mystery of this magic, they find that they need each other's skills. Maybe there is a prophecy involved that links their fates. This could lead to a series of adventures where they have to trust each other, even though their backgrounds are so different. It could also explore how Hermione's values might influence Dolohov or vice versa.