Harry Potter and all the characters involved do not belong to me, they belong to J K Rowling.
"Normal speech"
'Thinking'
Flashback
"Parseltongue"
Harry was stunned at Snape's words. He didn't hate him? But all his actions pointed to the opposite. True, they were getting along lately, with Snape stuck as a snake and all, but that was only because Snape was reliant on Harry. Though they did argue quite often… "Do you really not hate me Professssssor?" Harry asked hesitantly, "It'sss not that I doubt you or anything, well actually I do, but that'sss only becaussse you've never given any indication in the passst that you didn't hate me becaussse of who my father isss."
Snape sighed, why was he stuck with an idiotic Gryffindor who couldn't think? "Really, Potter, ussse your head for once, if there'sss anything in it. What wasss my role in the passst?"
"You were a ssspy…"
"Yesss! I wasss a ssspy, and head of Ssslytherin. Of courssse I couldn't be nice to any Gryffindorsss, not when I wasss head of Houssse to children of Death Eatersss, who were doubtlessssss reporting my actionsss back to their parentsss. I couldn't afford to make missstakesss asss a ssspy for the light, ssso I had to maintain my cover at all timesss."
"Oh," Harry replied, realizing just how dangerous Snape's role really was. "And I sssuppossse we didn't make it any easssier for you, did we?"
"You mossst certainly did not,"Snape snorted.
At that, Harry didn't know how to respond, so they sat in silence, until Snape reminded Harry that Madam Pomfrey was likely waiting for Harry to bring him in so she could check him over.
Once they had gone to the Hospital Wing, Madam Pomfrey had scanned Snape to make sure he was healing ok. She confirmed that Snape would be fine in a week if he didn't keep trying to escape, and explained to Harry that he kept finding himself unable to move because he was straining his body too much. When Snape had hissed at that, she had rounded on him and scolded him for continuously trying to escape and told him that he was only exacerbating his wound, and if necessary, she would keep him in the hospital wing in a tank under the body-bind curse to prevent him from escaping if he persisted in doing so. At that Snape had curled up grumpily in Harry's arms while he snickered at Snape's plight.
Madam Pomfrey had asked if there was anything else she could do for Harry, and when he asked her if she could find out what was keeping Snape trapped in snake form, she cast multiple diagnostic charms, but was unable to find anything wrong with him. His vitals were normal, his magical core was fine so it wasn't magical exhaustion keeping him stuck in that form. Her best guess was that because he was injured in that form, his magic was sustaining it until it deemed that he was fully healed.
Which is why Snape found himself curled up on Harry's pillow as he watched him performing some of the spells he had been reading up on, instead of trying to find a way to escape Potter. He had nothing better to do, and wanted to get back to his dungeons and his potions asap, and escaping would only extend the amount of time he was unable to do so.
"Why isn't it working?" Harry asked in frustration, not understanding why he was unable to perform the disillusionment charm, and inadvertently drawing Snape's attention to himself.
"You're doing it wrong, Potter," Snape sighed. He couldn't even be left to his thoughts without the bloody brat distracting him.
"Ssso how'sss it sssupposssed to be done then?"
"Firssst of all, you don't need to hit the object ssso hard, and sssecondly, you need to actually use your magic."
"I am usssing my magic!" Harry hissed angrily.
"No, you're jussst hitting the object with your wand and expecting it to become disillusioned," Snape retorted. "For you to disillusion sssomething, you need to know how the disillusionment charm worksss firssst. The charm changesss the physical propertiesss of the object ssso that it takesss on the appearance of the sssurroundingsss, thus rendering it 'invisible'. It is similar to how invisssibility cloaksss work. Sssome have disillusionment charmsss woven into the threadsss as it iss made, and othersss are woven out of hairsss of magical creaturesss that can disillusion themssselves. Therefore when performing the disillusionment charm, you mussst imagine the object taking on the appearance of itsss sssurroundingsss, and will your magic to make that change happen. Do you underssstand?"
"I think ssso."
"Then try it now," Snape told Harry. "Becaussse the charm isss wordlesssss, it will not be as easssy to perform as other charmsss, though with enough practice, all charmsss can be performed wordlessssly, and even wandlessssly, though it takesss a very powerful wizard to manage that."
Harry was still rather surprised that Snape had actually bothered to explain how the charm worked, and had yet to insult him, so when he tried the charm again, he was surprised to see that it had worked. Not completely, since he could still tell that the object was there, but it was hard to notice since it blended in with the surroundings fairly well.
"Better," Snape told Harry as he eyed the stool that he'd been practicing on, "But it'sss not entirely hidden yet. Hit it with a Finite, and try again."
On Harry's next try, he managed to do it, and he grinned at Snape. "You're a sssurprisingly good teacher sir. For a snake," he added cheekily.
"Brat."
