Well, perhaps there's a plotline where the goblins reveal long - held secrets to Harry because of his trust. These secrets could be about the origins of certain magical artifacts or the true history of Hogwarts. And this knowledge could then be used by Harry to fight against the dark forces in a different way than in the original series.
In some versions of this fanfiction, the trust in goblins might lead to a new form of magic being discovered. Since goblins have their own unique magical abilities and knowledge, Harry's connection with them could open the door to a different type of spell - casting or magical practice. This could potentially change the entire concept of magic in the wizarding world as Harry shares this new knowledge with his friends and allies.
One interesting plotline could be a goblin uprising in the wizarding world. They might feel oppressed by wizard laws and decide to fight for more rights. Another could be a goblin - Harry Potter alliance. Maybe Harry discovers that the goblins have a secret that can help him defeat Voldemort and they team up. Or perhaps a story where a goblin character befriends Harry and shows him a whole new side of the wizarding economy that is controlled by the goblins.
In some fanfictions, the goblins could assist Harry in learning about his family's true history and the secrets they left behind. This might involve them taking him to secret places within Gringotts that are not known to most wizards. The goblins' skills in deciphering ancient runes and their understanding of the magical economy could play a big role in this. For example, they could reveal that there are certain magical items that his family had stored away for a time of great need, and these items could give Harry an edge in his battles.
Another possible plotline is the relationship between Harry and the goblin community. How do they accept him as one of their own? There could be some goblins who are against the idea of adopting a human, and Harry has to prove himself worthy. This could lead to a lot of internal conflict within the goblin society as well as Harry's own personal growth.
It could strain his relationships with some pure - blood wizards who are prejudiced against goblins. They might see Harry's trust as a betrayal of wizarding traditions.
One interesting plotline could be how the characters deal with the complex nature of goblin debt. For example, Harry might find himself in a situation where he has to repay a debt to the goblins in a unique way, perhaps by using his magical skills in a task that benefits the goblin community. This could lead to a series of adventures and new relationships with goblin characters.
In certain fanfics, the goblins might be helpful in saving the wizarding world from a new threat. Maybe there's a new dark force emerging, and the goblins, with their unique magic and knowledge of the magical realm, work together with the wizards to defeat it. They could use their underground network and resources to gather information and strategize against the enemy.
Another plotline might involve Harry learning ancient goblin magic from his new friends. This could give him an edge in battles against the Dark Arts, as it's a type of magic not commonly known in the wizarding world. He could then share some of his own wizarding knowledge in return, strengthening the bond between them.
One interesting aspect in some fanfiction is the goblin society. They may have complex hierarchies and cultural traditions. There could be goblin characters who are rebels against the traditional goblin - wizard relationship, seeking more equality or even trying to take over wizarding institutions.
One interesting story could be about a goblin who forms an unlikely alliance with a Hogwarts student to solve a mystery in the wizarding world. They might team up to find a lost magical artifact that has significance to both goblin and wizarding cultures.
One interesting plot could be a goblin rebellion against the wizarding world's control over their banks. They might use their knowledge of magic and hidden tunnels to stage a takeover.