What could happen when Harry goes to Hermione's house in fanfiction?

In the fanfic, Harry might have a study session with Hermione. They could go through some old magic books, looking for answers to a mystery at Hogwarts. Maybe they'll find a new spell or a clue about a hidden part of the school's history.

Well, perhaps Harry could make new friends in the fifth house. He might discover some hidden secrets or unique magic that is specific to that house.

Well, they could meet younger versions of themselves and their friends. It would be really interesting to see how they interact. They might also try to give some hints or advice to their younger selves, but they have to be careful not to disrupt the timeline too much. And they could discover secrets that were long forgotten in the present time.

He might meet some interesting new friends. In fanfiction, the gay club could be a place full of unique characters. Harry could engage in deep conversations about various topics like art, music or the LGBT+ community's experiences.

Well, it could be that the teacher suspects some dark magic activities in the alley and takes Harry along to show him how to detect and deal with such things. They might encounter some dodgy characters along the way, like shady potion sellers or wizards trying to sell illegal magical artifacts.

He might encounter some strange magical creatures that are only found underground. For example, there could be a new type of goblin or a magical mole with special powers.

He could encounter a new magical creature. The goblins at Gringotts are known to have various magical creatures guarding different vaults. Maybe Harry comes across a rare and friendly creature that helps him on his journey. For example, a small fire - breathing dragon that he befriends and it later aids him in a battle against Voldemort's forces.

In this fanfiction, Hermione could be on a mission to retrieve a valuable item from Gringotts. It might be an heirloom of her family that was wrongfully taken and stored there. Along the way, she has to face many challenges like dealing with the goblins' tricky rules and overcoming some magical traps. She may also meet some unexpected allies or enemies within the vaults of Gringotts.

He might meet some strange magical creatures there that are used for experimental treatments.

In some fanfictions, when Harry Potter goes through the mirror, he might find himself in a parallel magical world. This world could have different versions of his friends and enemies, and he may have to face new challenges to find his way back to his own world.