The plot could revolve around a magical event at King's Cross Station where Snape's past and Hedwig's presence are intertwined. For example, a time - distortion spell occurs at the station, and Snape is transported back to a time when Hedwig was just a young owl. He then has to make sure that Hedwig gets to Harry in the future, all while dealing with his own past demons and secrets.
Perhaps in the fanfiction, Hedwig is lost near King's Cross Station. Snape, who is there for some mysterious reason, decides to help find Hedwig. As he searches, he starts to understand the significance of Hedwig to Harry and through this, his view of Harry softens a bit. It could be a story about unexpected connections and growth in Snape's character.
In the fanfiction, Hedwig could be carrying a small parcel that she drops near Snape. Snape, out of curiosity, picks it up and discovers it has something to do with Harry. This could lead to a conversation - like interaction where Snape talks to Hedwig as if she can understand, expressing his mixed feelings about Harry. Hedwig could then hoot in response, almost as if she's giving her own opinion.
It could be a story where Hedwig serves as a sort of guide for Snape in the afterlife. Maybe she shows him the good he did that was overlooked in life.
Perhaps she is half - vampire herself. This would create a lot of internal conflict as she tries to balance her human side and her vampire instincts. She could also be in a love triangle with a vampire and a human, which would add a lot of drama to the story.
Well, perhaps Hedwig could be magically transformed into a dragon. Then she might go on adventures, using her new dragon abilities like flying faster and breathing fire to protect her wizard friend from dark forces.
The plot could start with Hermione accidentally stumbling upon a time - travel device or spell. She ends up in the past where she meets Lily and Snape. She quickly realizes that she can't just mess with the past without consequences. So, she tries to subtly influence them. For Snape, she might try to nudge him towards a path where his love for Lily doesn't turn into bitterness. For Lily, she could be a confidante, sharing secrets from the future about the wizarding world's future challenges.
One plotline could be that Snape is initially confused in the afterlife and Hedwig appears to him, bringing a sense of calm. They start to communicate in a way that was not possible in life.
The plot could start with Harry waking up as an owlet in Hedwig's nest. He would have to adapt to his new form, learning how to fly and hunt like an owl. Meanwhile, Dumbledore might suspect that this is part of some dark magic plot and start an investigation. And Harry, in his owlet form, might discover secrets about the wizarding world that he couldn't as a human. It could also explore how his relationship with his friends changes in this new state.
The plot could revolve around Hermione being embarrassed about her period cramps in front of Snape. However, Snape, having known Lily Potter (Hermione might remind him of her in some ways), decides to be kind. He could share with her some of the old remedies that were used in the wizarding world for such ailments. As they interact more, Hermione begins to see Snape in a different light, and Snape starts to soften his attitude towards Hermione. This could lead to a series of events where they bond over this rather personal situation.
A fanfiction plot could revolve around Lucy being cursed. The curse affects her ability to use the Celestial Spirit King Star Dress properly. She then has to go on a quest to find a cure, traveling to different magical lands and meeting new characters. Along the way, she discovers secrets about the star dress that were previously unknown, like it having a hidden power that can only be unlocked under certain conditions. As she searches for the cure, she also has to fend off those who would take advantage of her weakened state.
One interesting plot twist could be that Severus Snape, as a 'king' in the fanfiction, discovers a long - lost magical art that gives him the power to change the past. This could lead to him preventing some of the tragedies that happened in the original Harry Potter story, like Lily's death. Another could be that he rules over a hidden magical realm where the rules of Hogwarts and the wizarding world as we know it don't apply, and he has to constantly defend this realm from dark forces that want to take over.