One idea could be a time - travel plot where Harry goes back in time and McGonagall is much younger. They form an unexpected bond during a dangerous situation at Hogwarts that gradually turns into a deeper, more romantic relationship. But they have to keep it a secret due to the age difference and the rules of the wizarding world.
A possible plot is that there's a magical competition in Hogwarts. Hermione and McGonagall end up being on the same team in an unexpected turn of events. They have to rely on each other's unique skills. Hermione's quick thinking and McGonagall's vast knowledge combine to overcome the challenges in the competition. During this time, they learn a great deal about each other and their relationship evolves in a positive way.
One idea could be a story where Hermione becomes McGonagall's apprentice in a special area of magic that's not taught in regular classes. They could go on adventures to find ancient spells and artifacts together.
Maybe Harry and Amelia are from two different worlds. Harry is from a world of magic and Amelia from a non - magical world. They accidentally cross paths when a magical portal opens up. They then have to learn about each other's worlds and help each other out in various situations, such as Amelia helping Harry understand non - magical technology and Harry showing Amelia the wonders of magic.
Perhaps in the fanfiction, Vernon discovers a hidden magical talent of his own. Harry, upon finding out, has to decide whether to help Vernon develop it or keep it a secret from the wizarding world as Vernon is a Muggle. This could lead to a lot of comical and tense situations.
Perhaps Loki and Harry find themselves in a situation where they have to swap powers for a day. Loki has to deal with Harry's magic wand and spells, while Harry has to handle Loki's shape - shifting and illusions. This could lead to a series of comical and also character - building moments as they learn from each other.
A possible plot could be that Harry and Nagin are both chosen for a special task in the wizarding world. They initially clash due to their different personalities but gradually learn to work together and form a strong bond along the way.
Perhaps in a Hogwarts where the normal rules are a bit more lax for a short time. Harry accidentally stumbles into Trelawney's classroom during one of her more intense divination sessions. She mistakes his presence as a sign from the stars. This leads to them spending more time together, and gradually feelings develop. They might go on a secret adventure within the castle grounds, exploring hidden chambers while their relationship blossoms.
Perhaps there could be a plot where a powerful dark magic affects the Hogwarts staff, and as a result, Minerva McGonagall ends up with a harem of wizards and witches who are magically bound to her for protection. This situation forces her to not only deal with the unexpected company but also find a way to break the spell without harming anyone.
One idea could be a story where Minerva and Severus have to team up to protect Hogwarts during a new, unexpected threat. Maybe a dark magic artifact is discovered near the school and they must use their combined knowledge and skills to keep it from falling into the wrong hands.
How about a story where Hermione discovers a hidden talent for transfiguration that even McGonagall is surprised by. They then work together to perfect this new form of transfiguration, but face opposition from some of the more traditional - minded professors. Or, in a post - war Hogwarts, they collaborate to reform the curriculum to include more practical and modern magic, all while dealing with the after - effects of the war on the students and the school.