Perhaps an old enemy from Snape's past, someone who has a long - standing grudge against him. This person could have tracked him down to the Shrieking Shack and finally got their revenge. It could be someone related to his days as a Death Eater or even from his school days when he might have made some enemies.
In Snape's death fanfiction, one common emotional reaction is shock. Readers are often stunned by his sudden death, just as it was in the original story. Another is sadness. Many fans feel a deep sense of grief because Snape was a complex and ultimately heroic character. There's also a sense of admiration that might be explored in fanfiction. His selfless act of protecting Harry Potter until the very end makes him a figure worthy of admiration, and fanfiction might delve deeper into how other characters come to fully realize his true nature and sacrifice.
There are several. Some focus on Snape's early days as a Death Eater. For example, in one fanfic, it details how he was recruited, his initial thoughts on Voldemort's ideology, and how he gradually started to question it. It also shows how his relationships with his fellow Death Eaters were formed and evolved over time.
Harry Potter might react with a newfound understanding. In the original story, he named his son after Snape. In fanfiction, this could be explored more deeply. He might feel guilty for not seeing Snape's true intentions sooner. Hermione could react with her typical intelligence - led analysis. She might try to piece together Snape's actions over the years and come to a more complete understanding of his character. Ron, on the other hand, might be more straightforward in his grief. He might be sad that someone who was on their side all along had to die in such a way.
One common theme is Snape's internal conflict. Since he was a double agent, fanfictions often explore the turmoil he felt between his loyalty to Voldemort as a Death Eater and his real allegiance to Dumbledore. Another theme is his relationships with other Death Eaters, like Bellatrix or Lucius.
There's also the possibility that it was an accident. Fanfiction often plays with the idea of magical accidents. Maybe a spell misfired during a demonstration or a fight that broke out among the Death Eaters that Snape got caught in the middle of, and as a result, he got injured.
Snape could be very cautious in his interactions. He would be constantly aware of the power dynamics. He might flatter the more powerful Death Eaters subtly to avoid suspicion. For instance, he could compliment Bellatrix on her loyalty to the Dark Lord. At the same time, he might try to intimidate the weaker ones to show that he's not to be trifled with. He might use his knowledge of the Dark Arts to his advantage in these interactions, like casually mentioning a difficult spell he's mastered to gain some respect.
One reason could be a surprise attack by Voldemort or his Death Eaters. Maybe they found a way to bypass all the protection spells around Harry and launched a sudden, fatal assault.
Some fanfictions might explore Snape's after - death journey to understand his own life. He could be reflecting on his actions, his loyalties, and his mistakes. There could be a scenario where he is given a chance to relive certain moments in his life, but with the wisdom he gained in death, and this could lead to different outcomes for the events in the Harry Potter universe.
Dumbledore is another character who is often included. Given his role in Snape's life and their shared secrets, in the afterlife they might continue their discussions or Dumbledore could be the one to help Snape come to terms with his past. Voldemort could also be mentioned in some fanfictions, especially if the fanfiction explores the long - term effects of Snape's actions against Voldemort in the context of the afterlife.