Perhaps Snape finds Harry drunk in a secluded part of the Hogwarts grounds. Snape, being strict, would likely want to punish Harry according to the school rules. However, he might also be secretly concerned about what led Harry to this state. He could start an investigation into whether someone influenced Harry to drink or if Harry was dealing with some personal problems that drove him to this. This could lead to a series of events where Snape and Harry have more interactions than usual, and Snape might even end up protecting Harry from any potential backlash within the school.
In the fanfiction, Snape might find Harry drunk in the Gryffindor common room. At first, Snape would be furious because it goes against the school's code of conduct. But Harry, in his drunken state, might let out some of his inner thoughts and feelings that he has been suppressing. This could make Snape realize that Harry is just a young boy dealing with a lot of pressure. Snape could then decide to handle the situation more delicately, maybe by giving Harry a detention where they actually have a heart - to - heart conversation instead of a typical punishment.
Snape is always complex. In this situation, he would be conflicted. On one hand, he has his long - standing dislike for Harry (or rather, his connection to James). On the other hand, as a teacher, he has a duty to take care of a student in distress. Drunk Harry would be a bit clumsy and giggly perhaps. His judgment would be clouded, and he might see Snape in a different light, not as the enemy but as someone who could help him, which could start to shift their relationship dynamic in the fanfiction.
One possible plot could be that Hermione was set up by some dark wizards who wanted to use her as bait to lure in Harry Potter or other members of the Order of the Phoenix. Snape, being a double agent, stumbles upon her while on one of his secret missions. He might initially be conflicted between his loyalty to the Death Eaters (on the surface) and his true allegiance. He decides to help Hermione, using his knowledge of dark magic to free her from the bindings and then they have to work together to escape the place before the real villains return.
Snape would likely be shocked and then enraged. Harry is supposed to be the hero of the wizarding world, and seeing him drunk would be a huge disappointment. He would most likely drag Harry to his office, lecture him about propriety and the expectations placed on him as a wizard, and probably assign some form of punishment like a long detention. But as he observes Harry more closely during this time, he might start to wonder what drove Harry to this and if there are deeper issues that need to be addressed.
In such a fanfiction, Hermione might first be shocked to see Harry in that state. She could scold him gently for getting drunk, as she is usually the more level - headed one. Then, she would probably try to sober him up, perhaps using a spell or getting him some water and food.
One possible plotline could be Snape finding drunk Harry in the Hogwarts corridors. Snape, being the strict teacher, might initially be angry but then realizes Harry is in a vulnerable state. He could take Harry to his office to sober him up and in the process, they have a conversation that reveals some hidden feelings or understanding between them.
He would probably be in shock. Snape has spent so much time around Harry in one way or another throughout his years at Hogwarts. His immediate reaction could be disbelief. He might stand there frozen for a moment, unable to process what he's seeing. Then, the full weight of the situation would hit him, and he could break down in a rare display of raw emotion.
It could be the pressure of being 'The Boy Who Lived'. Harry has so much expected of him all the time, and it might just be too much to bear.
One place to start looking for the missing fanfiction could be on large fanfiction platforms like FanFiction.net or Archive of Our Own. They have extensive collections of Harry Potter fanfictions. Check their search functions, maybe filter by characters (Snape and Harry Potter) and relevant tags.
Well, it could be that the snake has some magical powers that Harry discovers. Maybe the snake can talk and leads Harry to a hidden place in Hogwarts where there are ancient spells or treasures.
One plot twist could be that Snape is actually mentoring Harry on behalf of Dumbledore from beyond the grave. Maybe Dumbledore had some secret plan that he didn't get to fully execute, and Snape is now following through with it. Another could be that Snape discovers a new magical ability in Harry that no one else knew about.