One possible reason could be a powerful spell gone wrong. Maybe she was caught in the crossfire of a dark magic spell that Snape was either trying to counter or was involved in accidentally. Another reason might be extreme emotional shock. For instance, if she discovered some dark secret about Snape that was so overwhelming it sent her into a catatonic state.
Snape might initially be shocked. He's not one to show much emotion openly, but internally he could be very disturbed. He might start investigating what happened to Hermione immediately, using his skills in potions and magic to try and find a cure or at least understand the cause.
One popular 'hermione is catatonic' fanfiction is 'The Silent Hermione' which delves deep into how her friends deal with her condition. It shows the emotional turmoil of Ron and Harry as they try to reach her.
To write a 'hermione is catatonic fanfiction', start with a strong opening that shows Hermione in her catatonic state. Describe her appearance and the setting. Then, develop the story around the reactions of those around her. You can include flashbacks to show what led to this situation. When it comes to dialogue, make it meaningful. For instance, the conversations between the Hogwarts professors about her condition should be filled with concern and determination to help. You can also introduce new characters or magical creatures that might play a role in her recovery.
One great Snape and Hermione fanfiction is 'The Unbreakable Bond'. In this story, Hermione discovers a hidden side of Snape during her research in the Hogwarts library. Their relationship starts as a mentorship but gradually evolves into a deep friendship that defies the expectations of the wizarding world. It beautifully portrays their individual characters and how they can complement each other.
The 'time - travel' trope is also quite common. For example, Hermione might go back in time and interact with a younger Snape, which can lead to all sorts of new storylines and character developments.
Hermione might become more guarded at first. She is used to being independent and suddenly being 'gifted' to Snape is a big change. But over time, she could learn to be more patient and understanding. Snape, on the other hand, might soften a bit. His usual cold exterior could crack as he gets to know Hermione better.
It's hard to say who would be the clear winner. Hermione is intelligent and quick - witted, but Snape has years of experience and a great deal of magical knowledge. If it's a battle of words, Hermione might hold her own for a while, but Snape could use his authority to shut her down.
She might give him cold stares in class. Hermione is not one to shy away from showing her emotions through her expressions. So, every time Snape is in her line of sight, she could fix him with a withering glare that clearly shows her displeasure.
One possible reason could be a misunderstanding. Maybe Hermione thought Snape was involved in some dark plot against her friends. In the wizarding world, there are often secrets and deceptions, and if she got some false information, it could lead her to take such drastic action.