Another interesting plot could be that when Hermione travels back, she finds that Sirius has a much different personality than she expected. Maybe he's more cunning or more vulnerable. This changes the dynamic between them and leads to a more complex and emotional story. The author can then explore how Hermione adapts to this new version of Sirius and how they work together to face the challenges in the past.
One interesting plot could be Hermione and Sirius traveling back in time to prevent a certain dark wizard from rising to power. They could use their combined knowledge and skills to subtly change events. For example, Hermione's knowledge of magic history and Sirius' experience in the wizarding world could help them figure out how to stop the dark wizard's early supporters.
There are fanfictions where Hermione travels to a time when Severus is a young student and she becomes his mentor of sorts. She teaches him things that he would have never learned otherwise, like advanced Muggle - friendly magic. This creates a unique bond between them that defies the normal timelines and relationships in the Harry Potter universe.
A really intriguing plot is when Hermione time - travels to save Bellatrix from becoming evil. It challenges the whole idea of good and evil in the wizarding world. Another is when Bellatrix travels forward in time and meets Hermione in a modern - day Hogwarts. It's interesting to see how Bellatrix reacts to the changes in the wizarding world.
One great fanfiction could be where Hermione travels back in time to save Sirius. Maybe she uses her time - turner in a new and creative way. In this kind of fanfiction, she might have to outwit the Ministry of Magic and the Death Eaters who are after Sirius. She could change the course of the story by preventing Sirius from going to Azkaban in the first place.
A great plot idea would be that when they time travel, they accidentally change something in the past that has a huge ripple effect on the future. They then have to figure out a way to fix it. Maybe they make it so that Sirius was never disowned by his family in the past, which changes his whole life trajectory. This could lead to a completely different future for the wizarding world, and they have to race against time (again) to make sure the future doesn't go completely haywire.
One interesting plot could be that Harry and Hermione travel back in time to change a major event at Hogwarts, like preventing the opening of the Chamber of Secrets. They might use their knowledge from the future to outwit Tom Riddle before he becomes Voldemort.
Another plot might involve Tom Riddle traveling to the future where Hermione exists. He could be intrigued by her magic, which is different from what he's used to. He might try to use her knowledge for his own gain in the past, but Hermione is too smart for him and outwits him at every turn. This creates a battle of wits across time.
A plot where they are forced to team up to solve a mystery within Hogwarts. It could be a mystery related to the Chamber of Secrets or some other hidden part of the castle. During this time, they have to rely on each other's strengths, and Hermione starts to see Snape as an ally rather than just a strict teacher.
One interesting plot could be that Harry and Hermione discover a hidden time - turning spell. They use it to go back in time just enough to prevent Sirius from being framed in the first place. So they gather evidence of Peter Pettigrew's true nature before he can shift the blame onto Sirius.
Well, one intriguing plot is when Hermione goes back in time to stop Tom Riddle from making Horcruxes. It adds a whole new layer of drama as she has to figure out how to do it without disrupting the timeline too much. Another plot is when she travels back and tries to befriend Tom as a child, thinking she can change his future that way. In some fanfictions, the plot of Hermione getting trapped in the past while dealing with Tom Riddle's rise to power is also very interesting.