What are some interesting plot ideas for Harry Potter Chamber of Secrets fanfiction?

One idea could be exploring the backstory of the Chamber more deeply. Maybe look into how Salazar Slytherin really built it and what his true intentions were beyond just getting rid of Muggle - borns. Another could be a story where a new student discovers a hidden passage within the Chamber that leads to an even greater mystery. For example, they might find an ancient spellbook that has the power to change the very fabric of Hogwarts.

A cool plot could involve a time - travel aspect where a character goes back to when the Chamber was first created. They could then try to change things to prevent the current danger. Also, a fanfic could focus on the life of a minor character like Moaning Myrtle and how she copes with the new threat in the Chamber.

One idea could be to explore the backstory of the Chamber more deeply. Maybe there were other secrets or hidden chambers within it that no one knew about. Another could be to have a character from a different Hogwarts house be the one to discover a crucial clue about the Chamber this time, instead of Harry. For example, a Ravenclaw using their intelligence to figure out a riddle that leads to the discovery of a new aspect of the Chamber's mystery.

One idea could be a story where the Hogwarts Express itself is enchanted to lead students to a hidden entrance of the Chamber of Secrets. Maybe the train tracks shift and take the students on a wild ride to a secret location near the Chamber.

One interesting plot could be Daphne discovering a hidden secret passage in the Chamber of Secrets that even Harry doesn't know about. She could then team up with Harry to explore it further.

One idea could be that Draco and Harry are forced to work together secretly in the Chamber of Secrets to solve a mystery that Dumbledore suspects is bigger than just the basilisk. They find a hidden chamber within the Chamber of Secrets that contains a powerful magical artifact from the founders' time, and they must figure out how to use it to save Hogwarts.

One idea could be exploring the backstories of the students who were petrified. Maybe there are secrets about their families or something they knew that made them targets. Another idea is to focus on the relationship between the Weasley twins and how they might have secretly been investigating the Chamber of Secrets on their own. Also, a fanfic could explore what would have happened if Harry had found the Chamber of Secrets much earlier in the school year.

In some fanfictions, a plot twist might be that Tom Riddle had an older sibling who also had a connection to the Chamber of Secrets. This sibling could be trying to either stop or help Harry, adding a whole new layer of mystery and family drama to the story. Well, it really changes the dynamic as it makes the whole mystery of the Chamber not just about Voldemort's past but also about a part of his family that was previously unknown.

One idea could be exploring Ginny's deeper emotions during her time under the control of Tom Riddle's diary. Maybe she has hidden memories or feelings that she doesn't fully understand even after being freed. Another plot could involve Harry and Ginny secretly exploring more of the Chamber of Secrets after the initial events, finding hidden chambers or secrets within it. For example, they might discover an old wizard's study with spells and potions that were used in the past to keep the basilisk at bay.

One interesting plot twist could be that Ginny was secretly under a more complex spell than in the original story, which was cast by a hidden dark wizard in Hogwarts. This could lead to a whole new set of adventures for Harry to figure out how to break it.