There might be a fanfic where during the Triwizard Tournament, Harry gets cursed and Hermione has to find a way to break the curse. She races against time, using every spell and potion she knows. Meanwhile, she also has to deal with the tournament tasks on Harry's behalf. In the end, through her determination and love for Harry, she manages to break the curse and they both complete the tournament in an unexpected way.
One possible fanfiction could be about Harry and Hermione teaming up secretly during the Triwizard Tournament tasks. They might use their combined knowledge and skills to outwit the other competitors. For example, in the maze task, they could have a special code to communicate and find their way to the Triwizard Cup faster than anyone else.
She could research about the dragons' species and their habits. By knowing what scares them or what attracts them, she can give Harry useful tips. For example, if she finds out that a certain type of music calms a particular dragon, Harry can use that during the task.
A plot could be that the Triwizard Tournament tasks are magically altered to target Harry specifically, and Hermione has to use her skills to figure out who is behind it. Maybe a new dark magic is involved that she has to research. She then has to train Harry in new ways to face the challenges. For example, teaching him some ancient spells that are not commonly known.
Well, perhaps in the fanfic, Harry and Hermione find out that the dragons are actually magical guardians protecting a powerful ancient artifact within the tournament arena. They then have to decide whether to compete against the dragons as the rules state or try to work with them to uncover the mystery of the artifact. And also, the dragon that Harry is supposed to face in the tournament could have a special connection to his past that Hermione helps him uncover.
There are fanfictions where Hermione and Fleur become friends during the Triwizard Tournament. In some stories, they start to see past their initial rivalries. Fleur might initially see Hermione as just a book - smart girl, but as they face the challenges of the tournament together, they develop a mutual respect. Maybe they work together on the Yule Ball preparations within the context of the tournament, which helps to strengthen their bond.
In a fanfic like this, there could be a lot of drama. For example, Pansy might be conflicted because of her Slytherin loyalty and her growing feelings for Harry. Harry, on the other hand, could be dealing with his own feelings while also trying to survive the dangerous tasks of the Triwizard Tournament. Their relationship could start with a lot of bickering and then slowly turn into something more romantic as they face the challenges together.
In many fanfictions, the Triwizard Tournament intensifies their relationship. The shared danger and the challenges make them rely on each other more. For example, in some stories, Hermione helps Harry prepare for tasks, and this brings them closer as they spend more time together.
One common plotline is that Hermione participates in the Triwizard Tournament instead of Cedric. This gives her and Harry a whole new dynamic as they face the challenges together. Another plotline could be that there's some sort of magical interference during the Tournament that makes Harry and Hermione realize their deeper feelings for each other. For example, a spell gone wrong that makes them share their innermost thoughts.
A plot twist could be that the Triwizard Cup is actually a portal to a different dimension, and Harry and Hermione accidentally get transported there during the final task. They then have to find a way back while dealing with strange creatures and magic in this new dimension.