In such a fanfiction, they could be on a quest and the car could be a magical vehicle that malfunctions. Hermione might use her intelligence to try and fix it while Sirius uses his experience to protect them from any threats that come their way during this situation.
Well, perhaps the car is enchanted and out of control. Sirius Black, with his knowledge of the wizarding world and his brave nature, could be trying to stop the car from crashing. Hermione, being the brilliant witch she is, might be researching spells on the fly to help him. It could be a really exciting scenario where they have to work together to overcome this car - related magical mishap.
It could be that the car is a key element in a mystery they are trying to solve. Hermione and Sirius Black might be investigating something and the car holds clues. Maybe the car has some sort of dark magic attached to it. Sirius, with his street - smart skills from his time as an Animagus and Hermione with her vast book knowledge, would combine their skills. Hermione could analyze the magic on the car while Sirius scouts the area for any signs of danger related to the car's mystery.
They might use the car as a means of escape. Sirius could be driving the car while Hermione casts protective spells around it to keep them safe from pursuers.
She could inherit some of Sirius's traits. For example, his rebellious streak might make Hermione more willing to break the rules when it's necessary to achieve a greater good.
Well, one thing that could happen is that Hermione would be exposed to a whole new family dynamic. Sirius has his own wild past and rebellious nature. He might encourage Hermione to be more daring in her magic, perhaps showing her some spells that are a bit on the edgy side but still within the bounds of good magic. Also, she could learn a great deal about the Marauders from him directly, which would give her a new perspective on the history of Hogwarts.
Well, Sirius would probably first ensure Hermione's safety. He'd get her away from the source of abuse. Then, he might start to heal her emotional wounds by being there for her, listening to her. For instance, if she was abused at Hogwarts by other students, Sirius could take her to Grimmauld Place and create a safe haven for her.
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.
In this fanfiction, Sirius might find a new sense of family and belonging with the Potters. He could help James Potter in protecting Lily and Harry, adding an extra layer of defense. Maybe he'd also share some of his unique magical knowledge and skills with them.
Harry could also team up with Hermione and Ron. Hermione would use her extensive research skills to dig into the Ministry's files on Sirius. They might find that there were some irregularities in the trial process. For example, crucial evidence was withheld or fabricated. Ron, on the other hand, could use his family's connections within the wizarding world to gather more information about the people who were involved in the case against Sirius.
Maybe Sirius Black gets frustrated with Hermione's know - it - all attitude in the fanfiction. He could be tired of her constantly correcting others or trying to take charge all the time.
The main problem is that Sirius Black is from an older generation of wizards and has a very different set of values and experiences compared to Hermione. For example, Sirius was part of the Order of the Phoenix during the first wizarding war, while Hermione is dealing with the aftermath of the second wizarding war. Their perspectives on magic, society, and relationships are likely to be different. Moreover, Sirius has a rather dark past which might be hard to reconcile with Hermione's relatively sheltered Hogwarts life. It's a challenge to create a story where they can interact meaningfully without sacrificing the essence of either character.
In many fanfictions, Sirius Black might protect Hermione from various threats. For example, he could shield her from dark wizards who target her for her intelligence or her connection to Harry. He might also protect her from the more traditional Hogwarts bullies. His protective nature could stem from seeing her as a valuable member of the group around Harry, like a little sister figure.