Maybe a fanfic where the goblins of Gringotts go on strike. Since Harry has some influence with them due to his own vault and his adventures there, he gets involved in the negotiations. Along the way, he uncovers a plot by some Death Eaters who are trying to take advantage of the chaos to steal valuable magical artifacts from the bank. It would be a mix of politics, mystery and action.
One idea could be that Harry discovers a long - lost vault that contains a powerful and dangerous magical artifact. He has to figure out how to deal with it without causing chaos in the wizarding world. Another is that he uncovers a conspiracy among some of the Gringotts employees to steal from the vaults of important wizarding families.
One idea could be a story where a young wizard discovers a long - forgotten vault in Gringotts that holds the key to an ancient magic. Maybe it's a magic that was lost during the time of the founders of Hogwarts. Another plot could involve a heist at Gringotts, not by the main characters like in the original series, but by a group of dark wizards who are after a powerful and dangerous artifact. A third idea is that a character gets trapped in the deeper, more mysterious levels of Gringotts and has to find their way out while uncovering secrets about the wizarding bank's history.
One idea could be a story where a young wizard loses his Harry Potter - style robes near Gringotts. He then has to go on a mini - adventure to find them before an important wizarding event. Maybe he discovers a secret passageway while looking for his robes that leads to a hidden vault in Gringotts.
Well, a cool plot could be that the contents of Harry's Gringotts vault are not what they seem. Instead of gold and jewels, there are enchanted objects that start to come to life and cause chaos in the vault. He then has to team up with some unlikely allies, like goblins who have their own reasons for wanting to restore order in the vault. Also, it could be that Voldemort had a hidden plan related to Harry's vault all along, and Harry has to uncover it to finally put an end to the dark magic that still lingers.
One idea could be that the Head Goblin discovers a long - lost magical artifact hidden deep within the vaults of Gringotts. This artifact has the power to change the balance of magic in the wizarding world. Another could be that the Head Goblin forms an unlikely alliance with Harry Potter to protect Gringotts from a dark wizard who wants to steal all the gold and magical items stored there. Or perhaps the Head Goblin has a secret past related to Harry's family, and this connection unfolds throughout the fanfiction.
One interesting plot idea could be a crossover where a character from another fandom accidentally stumbles into Gringotts in the Harry Potter world. Maybe a time - traveling character who has to figure out how to navigate the wizarding bank's security and magical vaults without getting caught. Another could be a scenario where the goblins of Gringotts have a secret alliance with a group from another universe and Harry Potter and his friends have to uncover this plot that could potentially disrupt the wizarding economy. A third idea might be that a character from a different story has a special key or artifact that unlocks a long - forgotten and extremely powerful vault in Gringotts, leading to a race between the good and bad forces in the Harry Potter world to obtain what's inside.
One interesting plotline could be the discovery of a long - lost inheritance in Gringotts that has a powerful magical object. Maybe it's a wand with special abilities that can only be unlocked by a specific heir. This could lead to a race between different wizarding families to claim it.
Perhaps a fanfic where Lily Potter's spirit is able to communicate with Harry Potter during his difficult times at Hogwarts. She gives him advice and guidance that helps him through his struggles, like dealing with Snape's complex feelings towards him, or facing the challenges of the Triwizard Tournament. This would add an emotional and magical element to Harry's journey.
One plot idea could be that Crookshanks discovers a hidden passage in Hogwarts that leads to an ancient wizarding library. He then leads Hermione to it, and they find a powerful spellbook that helps them in their fight against the dark forces. Another could be that Crookshanks has a secret ability to communicate with other magical creatures in the Forbidden Forest and he enlists their help to save Harry from a dangerous situation. Maybe he can talk to the centaurs and they come to the rescue when Harry is surrounded by Death Eaters.
One idea could be exploring Bellatrix's backstory before she became a Death Eater. Maybe she had a complex relationship with her family that led her down the dark path. Another could be a story where she has a change of heart, perhaps due to an unexpected encounter with a character like Harry Potter. For example, she could see some of her own past self in Harry and start to question her loyalty to Voldemort.