AN: This story is unrelated to any of my previous works. This story is a murder mystery set in the fourth book during the tri-wizard tournament. I don't see this as a long and complex story as some of my others have become, but rather a shorter exercise in thinking of how it could be to have Snape as a private investigator. I don't see this as a guardian type of story either, although I hope that the principal characters will come to some sort of understanding. I've not written this kind of story before, suggestions and encouragement would be very helpful.

Please let me know what you think! I love comments, suggestions, and engagement from readers. I find input from others makes the story much more interesting!

Warnings: I am not JK Rowling and do not own Harry Potter or related characters. I merely play in the sandbox she built. This story is AU, though as canon compliant as I can make it given the circumstances. There will be original characters and spanking (cp) of a teenager, if those bother you then please read another fic. Abusive comments are summarily deleted.

Snape sat in his potions lab, enjoying the reverie of a quiet evening. Detentions were done and miscreants were sent to bed ahead of curfew, and his grading had been caught up. He had the pleasure of a new potion to work on and no conceivable interruptions between now and breakfast. It was rare thing indeed that he would have the luxury of such an evening.

Just as he added the powdered asphodel to his infusion, he heard a small knock at his door. He didn't know who it could be at this hour, as Dumbledore would not have given him the courtesy of a knock. It must be a Slytherin prefect with a problem with a student.

"Enter," he intoned, casting a stasis charm over his potion.

"Good evening, professor," a girl greeted him, and only his clear use of occlumency hid his surprise as to who that voice belonged to. Why would that particular girl be visiting him just before curfew?

"State your business," he told her curtly. "I have a busy evening ahead of me."

"I have come to ask for your help," she told him. "Please, may I have a minute?"

"Sixty seconds," he told her. "And this had better be good."

"Harry needs your help," she told him plainly. "And I have come to ask for it."

"Surely there are many far more suitable for such a task," Snape snarled at her. "I believe he has hoards of fans at his disposal and a head of house and headmaster that barely believe he could do anything wrong."

"I think you are the only one that can help," she told him simply. "Dumbledore and McGonagall have too much sympathy for him, and that's leading to them excusing him rather than exonerating him."

"Stop babbling and tell me what has happened," he snapped at her. "Or leave my lab at once."

"Someone has killed one of the students from Durmstrang," she explained. "Harry will be accused."

"Do I look like an Auror?" he asked her incredulously. "What makes you think I can investigate a murder?"

"I believe it is a plot to frame Harry," she told him. "And the boy was poisoned. I have gone through this quite logically, and really you are the best person. I don't trust the Aurors, the ministry has not shown itself to be trustworthy."

"I'm surprised that you find me trustworthy," he snapped.

"You have never lied to me," she answered with feeling. "And never pandered to anyone. People know exactly what you think. I think that sort of trustworthiness is what we need."

Snape barely suppressed a smirk, the chit had no idea how much he suppressed how how much of his life he spent lying. "And why would I agree to this insanity?" he quipped. "This is a murder, not a prank war with Hufflepuff."

"I will do anything," she offered, trying to keep the note of desperation out of her voice. She knew he could bargain for terrible things – and she would do it. She was that desperate.

"Anything?" he asked, his voice dark and menacing.

"Anything," she repeated, swallowing down her fear.

"Then I would like information regarding the theft of several ingredients from my private potions cupboard that are incidentally used for making Polyjuice Potion," he told her firmly, relishing in the shock that lit her face.

"That's what you want?" she asked incredulously.

"I want all pertinent information to all related rule-breaking," he confirmed. "And I want the the ability to punish the wrongdoers how I see fit, up to and including the cane."

Hermione blinked, surprised. "The cane isn't used at Hogwarts," she argued.

"It's not used in Gryffindor," he corrected. "But you know as well as I do that there is no rule prohibiting in, and in fact there's a long tradition of its use."

"I can't guarantee others submitting themselves to your punishment," she told him carefully. "I can try, however."

"What I would require was your cooperation," he told her with a menacing glare. "And the information that you possess. I have ways to ensure the cooperation of others."

"I agree to confess my wrongdoings," she told him, forcing herself not to think about the consequences to her agreement.

"Excellent," he replied. "Now tell me."

"Now?" she squeaked. "I thought you would help Harry first."

"Out of the two of us I believe I am the one who is the most 'trustworthy,'" he replied acerbically. "However, I would be willing to make a wizard's oath."

"You promise to help Harry if I tell you everything I know about the ingredients and let you punish me for it?"

"I vow to help Harry with this accusation in return for your supplying the requested information and submitting to what I deem as appropriate punishment for the misdeed, up to and including the cane."

Snape felt the ripple of the oath cover him and then vanish, but he knew that the oath didn't vanish. It didn't bother him either, for surely if Dumbledore's golden boy were in trouble Dumbledore would request his help anyway. But it intrigued him that this young Gryffindor would not only put so much faith in him but also to be willing to give him whatever he asked for in return. That type of loyalty hit a chord for him, even if it was just part of the detestable Gryffindor ethics.

Hermione recognized the vow, and bit her lip in nervousness. She knew that he would keep his end of the bargain, but she also knew the information she had was both going to make him furious and also not satisfy what he thought she was going to tell him. And she was becoming increasingly convinced that this was going to end in a very painful way for herself.

"In second year I took advantage of a distraction and stole from you," she confessed. "I stole a boomslang skin. I then used it to brew Polyjuice Potion. My plan was to use that potion to then break into the Slytherin common room to try and ascertain if Draco Malfoy knew anything about the heir of Slytherin. In order to do that, I dosed Crabbe and Goyle with a sleeping potion. However, the potion went wrong and instead of a hair from the Slytherin girl I intended, I had a hair from her cat."

"You were in the infirmary for two weeks," he remembered, his eyes narrowing.

"I was," she agreed.

"And you were not alone."

"I wasn't," she agreed. "But I did not agree to confess anyone else's wrongdoings."

Snape nodded, knowing he would come back to that later. "I was more interested in your more recent thefts," he told her. "I have had missing ingredients all year."

"That was not me," she told him firmly. "Nor any compatriot of mine."

"I thought you couldn't confess another's wrongdoing," he told her.

"I won't," she answered stubbornly. "But I can confess their innocence. I vow on everything that I hold sacred that we have not stolen any Polyjuice Potion ingredients from you since second year."

"What about Gillyweed?" he asked, his eyes narrowing.

"That wasn't part of our agreement," she quipped back. But then, deciding that it was not going to damn her any more, she told him, "Harry did benefit from stolen Gillyweed. That is all I'll say on the topic."

Snape grit his teeth together in frustration, and quickly reviewed the story. "In second year you dosed Crabbe and Goyle, and stole a cat hair from an unnamed Slytherin girl. Therefore, you had two accomplices. I think any idiot would know who they are."

"You don't have proof," she countered, sounding more confident than she felt.

"I don't need proof," he answered back in his silky, menacing voice. "I have you. Your infamous trio has one week to confess to their wrongdoing and submit to their punishments. Which, let me be clear, will involve bending over my desk and feeling the business end of a large paddle."

"And if they don't?" she asked lowly, already deciding that they wouldn't.

"Then it will be you," he told her. "And it will be the cane. I suggest you research the differences as that should help you make your decision. Now, will you promise to tell them this information or will you leave it to me to convey?"

"I will tell them," she nodded.

"Do not think to be a foolish Gryffindor and spare your friends by not telling them," he told her, his voice smooth. "I will know if you fail to tell them by potions tomorrow."

"Harry might not even be around to accept his punishment!" she told him incredulously. "Didn't you hear me tell you that he's been accused of murder? He could be in Azkaban!"

"If I fail so miserably as to not clear his name by next Sunday evening, then I will cancel his punishment," Snape agreed, nodding. "But not yours."

Hermione nodded, that was fair. Although she felt a little faint at the idea of bending over and letting Snape take a paddle to her, she carefully schooled her features and forced her mind to abandon that mental picture. It didn't matter now, it had to do with saving Harry.

Snape looked over the girl that had always been such an enigma to him. She was clearly intelligent, arguably the brightest witch of her year if not in the whole school. But yet she was placed in Gryffindor, and her friends were Potter and the sidekick that Snape had not discerned a use for. But here she was, willing to do anything to save her friend. And she had barely blinked when he had told her that she would get the paddle, a sentence that would send most Slytherins into a tizzy of apologies and bargaining. But there she stood, firm in her resolution and loyalty to her friend, and willing to sacrifice anything for them. He saw her for the first time for the Gryffindor that she truly was.

"You will now tell me everything you know about the murder," he told her. "Do not leave out even the slightest detail, even if it seems foolish. I also need to know every detail about yours and Potter's whereabouts in the last twenty-four hours."

"But that's part of the problem, professor," she told him respectfully. "Nobody knows where Harry was during the time of the murder, not even Harry. He's had some sort of memory charm performed on him or something. He's half afraid that he did commit the murder."

"But you are certain of his innocence?" Snape asked, his eyes narrowing.

"I am," she replied solidly. "Would I come to you and make the bargain that we made if I wasn't?"

Snape had to admit that she had a point. He looked at her critically once more, and asked. "Why are you so certain?"

"Because I know him, professor," she replied, her eyes lowering with emotion. "He would never do such a thing. And if he did, it would be under the Imperious Curse."

"Now, Miss Granger," he told her in a tone that brooked no disobedience. "You will tell me everything that you know about this situation.

Nodding, Hermione began.