It could be that Hermione discovers Snape's secret efforts to protect the students all along. This new - found knowledge makes her see him in a different light. When he accidentally brushes against her or holds her to keep her from falling in a chaotic situation, she feels safe in his arms because she now trusts him completely.
One scenario could be that Snape saves Hermione from a Dark Arts spell gone wrong. As he catches her in his arms after deflecting the spell, she feels safe because he has just rescued her life.
Maybe there is a schoolwide attack, and Snape is the one who finds Hermione hiding and scared. He takes her into his arms to comfort her, and his calm and powerful presence makes her feel safe. In fanfiction, we can explore these emotional moments between unlikely characters.
One possible reason could be that Snape has shown unexpected kindness to Hermione in the fanfiction. Maybe he has protected her from some danger secretly, which makes her feel she can rely on him and thus feel safe.
Fanfiction allows for a lot of creativity. Perhaps the story is set in an alternate universe where Snape and Hermione have a different dynamic. Snape could have redeemed himself much earlier in this universe, and Hermione has come to understand his true nature. So when he holds her, she feels safe because she knows he is on her side, that he has changed from the cold and strict professor she knew in the original story.
Perhaps in the fanfiction, there's a curse that was meant for Snape but Harry jumps in to take it. As Harry is dying in Snape's arms, Snape has a moment of deep reflection. He might think about all the times he could have been kinder to Harry, and how Harry has now become a symbol of the good that Snape had long forgotten in his own life. And this moment of Harry's death could be a turning point for Snape's character development in the fanfiction.
One possible scenario could be a moment of intense conversation where Hermione is sitting in Snape's lap and they are having a deep discussion about magic theory that only they understand. It might be a turning point in their relationship in the fanfiction world.
One reason could be Snape's knowledge. Hermione, being a knowledge - seeker herself, might feel safe knowing that Snape has a vast understanding of magic, especially the darker aspects. So, she believes he can keep her safe from any threats related to that knowledge.
One reason could be the re - imagining of Snape's character. In fanfiction, he might be kinder and more understanding towards Hermione than in the original story. So, she feels safe in his presence.
One possible scenario could be that Hermione confronts Snape about his unfair treatment of Gryffindor students. Maybe she has evidence of him being overly harsh and she stands up to him in a classroom setting.
Well, one possible scenario could be that in the fanfiction world, there are dark wizards or forces targeting Hermione for her knowledge or power. Snape, with his skills and knowledge of the dark arts, could use his magic to shield her from attacks. For example, he could set up protective spells around her when she is studying in the library or traveling around Hogwarts.
In a fanfiction, Snape might be hard on Hermione during detention. He could assign her extremely difficult tasks that are almost impossible to complete within the given time, just to test her limits. For example, making her organize his entire store of potion ingredients in a very specific and difficult - to - achieve order.
One possible scenario could be that they are on a secret mission. Maybe they are looking for some hidden knowledge or a powerful magical artifact that Snape had stashed away in his house. Another scenario might be that Harry is in hiding at Snape's house for some reason, and Hermione comes to check on him and bring him supplies or important news. It could also be that they are reminiscing about Snape after his death and going through his things to understand him better.