One possibility is that the story could explore the complex relationship between Hermione and the Death Eater. Hermione is known for her intelligence and she could use her wits to manipulate the Death Eater into helping her. The Death Eater, on the other hand, might be intrigued by Hermione's boldness and knowledge, and gradually come to respect her, leading to an unexpected partnership.
Well, in such a fanfiction, perhaps the Death Eater could initially be reluctant to help Hermione. But if there's some common goal, like stopping a greater evil in the wizarding world that might affect both the good and the Death Eaters' side, they could form an uneasy alliance. For example, a powerful dark magic artifact is about to be misused by a new dark wizard and Hermione realizes she needs the inside knowledge of the Death Eaters to stop it.
It could be that the Death Eater has a change of heart. Maybe he or she was forced into being a Death Eater in the first place. When Hermione approaches for help, they see it as a chance to redeem themselves. They might share some secrets about Voldemort's old lairs or hidden plans that could help Hermione in her fight against the remnants of the dark forces.
The story could start with Hermione being in a desperate situation where she has exhausted all other options. She then decides to seek help from a Death Eater she believes might have some useful information or resources. At first, there would be a lot of tension and mistrust between them.
In such a fanfiction, Hermione might initially be in great danger. The Death Eater could try to capture her to use as leverage against Harry Potter. Maybe she uses her quick wits and vast magical knowledge to outsmart the Death Eater at first encounter.
Another idea is that Sirius, as a Death Eater, has some information that Hermione needs to defeat Voldemort. She has to convince him to give it to her while also dealing with his newfound allegiance. It could be a race against time as other Death Eaters suspect Sirius of being unfaithful to their cause, and Hermione has to protect him while also getting the crucial information.
It could also be that Hermione is on a mission to gather information. By helping the Death Eater, she hopes to gain insider knowledge about the Death Eater's group or their plans. This would be a strategic move on her part, using the situation to her advantage in the fight against the dark forces.
In some fanfictions, Hermione might be a Death Eater spy due to a complex backstory. Maybe she was blackmailed. For example, if the Death Eaters threatened to harm her Muggle - born parents, she could be forced to spy for them. This would be a huge deviation from her canon character, but in the realm of fanfiction, it allows for exploring different character arcs and moral dilemmas.
Well, the Death Eater might save Hermione from a dangerous situation. For example, if she's captured by other dark wizards, the Death Eater could use his influence within the dark side to free her. This would be a huge shock to Hermione and the other characters, and it would lead to a lot of mistrust initially.
Well, one possibility is that Hermione uses her quick wits and magic skills to defend herself. She might immediately cast a stunning spell or a protective charm. For example, she could use the Protego spell to create a shield between her and the Death Eater. Then, she would likely try to find a way to escape or call for help. Maybe she'd use her Time - Turner (if she still has it in the fanfiction context) to go back a few minutes and avoid the encounter altogether.
Well, one possibility is that Hermione uses her intelligence to outwit the escaped Death Eater. Maybe she sets up a series of magical traps. She could use her knowledge of spells like the Stunning Spell or the Binding Charm to keep the Death Eater at bay until help arrives.
In fanfiction, when Hermione talks to a Death Eater, she might try to persuade the Death Eater to abandon their dark ways. For example, she could use her intelligence and knowledge of the wizarding world to show the Death Eater the error of their beliefs. Maybe she would bring up the harm that Voldemort has caused and how following him is only leading to destruction.
One reason could be that the Death Eater has a family member who was saved by Hermione or her friends. So, out of gratitude, he decides to help her.