Maybe Snape was in a really bad mood and Harry happened to be in the wrong place at the wrong time. Snape is often portrayed as a complex character with a lot of pent - up anger, and Harry might have unknowingly triggered it.
Harry might be shocked at first. After all, being hit by a teacher, especially Snape, is unexpected. He could immediately get angry and want to retaliate, but hold himself back because of the situation.
Perhaps Snape discovers some dark plot involving the Dursleys that could harm Harry more than he initially thought. The Dursleys were known to be cruel to Harry, and Snape might have found out that they were involved with some Death Eaters or dark magic users who planned to use Harry in a harmful way. So, he decides to rescue Harry to prevent this from happening.
Maybe they want to show Snape some kindness. Snape is often seen as a strict and unapproachable figure. Harry and Draco might have realized that beneath his tough exterior, he has a soft side. Sending a teddy bear could be a symbol of their new - found understanding and an attempt to break the ice with him.
One possible reason could be that Snape is starting to see Harry in a different light. Maybe he realizes that Harry has been through a lot and has a moment of empathy. It could also be a sign of a deeper, unspoken connection developing between them in the alternate universe of the fanfiction.
One possible motive could be Snape's complex relationship with Harry's father. Snape might see Harry as a way to get back at James in some twisted way. He could also be acting out of a sense of duty to the Dark Lord, believing that taking Harry by force is part of some larger plan to gain power or favor.
One possible reason could be for misjudging Snape all those years. Harry might have finally realized that Snape was on the good side all along, working as a double agent against Voldemort. This realization could lead to his apology as he understood how much Snape sacrificed and how wrongly he was treated by Harry and others at Hogwarts.
One possible reason could be that Snape suspects Harry of something. Maybe he thinks Harry is involved in some sort of mischief or is in possession of something he shouldn't have. Snape has always been a bit of a mystery and is often distrustful of Harry, so this action might be his way of getting to the bottom of things.
One possible reason could be punishment. Snape has always had a rather thorny relationship with Harry in the original series. He might see this as a way to assert his authority over Harry. Maybe Harry has done something in the context of the fanfiction, like accidentally messing up Snape's potion ingredients or getting into an area of Snape's house where he wasn't supposed to be.
It could be that Harry demonstrates a great deal of magical talent in a new and unique way in the fanfiction. Snape, being a Potions master and a powerful wizard himself, would be impressed by such talent. Also, if Harry shows an understanding of something that Snape values deeply, like loyalty or sacrifice, it would make Snape have a positive view of him in the fanfiction.
One well - known 'Snape hits Harry' fanfiction is 'The Unseen Consequences'. It delves into the complex relationship between Snape and Harry after such an incident. It shows how Harry's trust in Snape is further shattered and the reactions of the other Hogwarts faculty.