Perhaps in this fanfiction, Narcissa saves Harry's life in a very unexpected way. Harry feels indebted to her and starts to spend time with her to repay the debt. But during this time, they find that they have a lot in common, like their love for certain magical creatures and their secret desires for a more harmonious wizarding world. Their relationship grows from friendship to love, and they decide to marry. This would shock the wizarding society as it goes against all the norms and expectations, but it could also lead to a very interesting exploration of how people can change and how love can be found in the most unlikely places.
One possible plot could be a story where the wizarding world is in a state of great upheaval after the war. Harry, in his quest to bring about true peace and unity, finds himself working closely with Narcissa. Over time, they develop a deep understanding and respect for each other. Narcissa, having lost so much in the war, is drawn to Harry's sense of justice and kindness. Harry, on the other hand, sees Narcissa as more than just a Death Eater's wife. Their relationship blossoms in secrecy at first, as they both know it will be a shock to the wizarding community. Eventually, they decide to marry, much to the dismay and confusion of many, but also as a symbol of a new beginning that transcends old grudges.
One possible plot could be that Harry grows up with a different perspective on the wizarding world. Narcissa might shield him from the more extreme pure - blood ideologies in her own family. He could still have his natural talent for magic but be trained in a more Slytherin - like way, focusing on cunning and self - preservation. And he might have a different relationship with Draco, perhaps more of a brotherly bond.
There are many fanfictions on this topic. Some might explore how Narcissa's pregnancy would change her relationship with the Malfoy family and their stance in the wizarding world. It could also show how she might deal with the impending birth during the chaotic times in the story.
In some fanfics, a plot twist could be that Narcissa was actually a spy for Dumbledore all along, and she was the one feeding him information about the Death Eaters. This completely changes the dynamics between her and Harry as they are on the same side without Harry even knowing.
One common theme is redemption. Narcissa was a Death Eater's wife, and in many fanfictions, she tries to redeem herself through her interactions with Harry. Another theme is the blurring of the lines between good and evil. Since Harry represents good and Narcissa was on the 'bad' side originally, their relationship in fanfics often challenges the traditional view of good and evil.
One unique fanfiction I remember is set in an alternate universe where Narcissa is a spy for the Order of the Phoenix from the very beginning. Harry stumbles upon her secret and they end up working together closely. The plot is full of twists and turns as they try to outwit Voldemort and his Death Eaters. It also delves deep into Narcissa's character, showing her as a strong and complex woman with her own motives and desires. In this story, their relationship is a key factor in the fight against the Dark forces.
One idea could be that Harry discovers Narcissa has a secret mission to undermine Voldemort from within. Maybe she's been secretly helping the Order of the Phoenix all along and Harry stumbles upon this knowledge.
One popular type might be those that focus on their relationship within the complex wizarding world. For example, some fanfictions could explore how Narcissa's loyalty to her family and the Dark Lord might interact with Harry's role as the 'Chosen One'. It could show how their paths cross in unexpected ways, like in a political intrigue within the Ministry of Magic where they have to form an uneasy alliance to achieve their respective goals.
In this fanfiction, Dani could be a foreign exchange student from a different magical school. Harry is intrigued by her different magical knowledge and culture. They start to study together, comparing spells and magical theories. Their relationship blossoms as they work together to solve a mystery that threatens both of their schools. Their marriage would then be a symbol of unity between the two magical institutions, with students and faculty from both schools attending the wedding.
A plot could involve time - travel. Harry, for some reason, is sent back in time and meets a younger Narcissa. He gets to know her before she becomes involved with the Dark Arts. They form a bond, and as Harry tries to change the future to prevent some of the tragedies in the wizarding world, their relationship deepens. Eventually, they marry in this altered timeline, and Harry has to deal with the consequences of changing the past and his new relationship with Narcissa.
One possible plot twist could be that Narcissa uses her influence as Harry's godmother to protect him from the darker forces within the wizarding world in a more public way than in the original series. For example, she might openly oppose Voldemort's regime to save Harry, which would put her in a very dangerous position as she was once part of the Death Eater families.