"Well, Miss Granger, let's get right down to it," commanded Professor Vector. The witch moved to her office's floo, tossed in a pinch of powder, and barked an order for two lunches. She returned to the seat at her nearly empty desktop and hawkishly examined Hermione. Students seemed to either love or hate Professor Vector, who was notoriously difficult in the classroom and short and sharp outside of it. To put it mildly, she was about as cuddly as a tentacula plant. Then again, there was something about her demeanor that Hermione had always liked. Septima Vector was no nonsense, like Professor Snape in many ways.

"Professor, I must preface showing you my work with several facts which are secret to the majority of people in the Light for strategic reasons. While I'm not in a position to ask you for an oath in order to protect that information, I must insist that you understand the gravity of what I'm about to tell you and the strictest necessity to keep it confidential."

"Then why have this meeting with me at all?" she shot back.

"Frankly, you need the calculations that I've been working on. I won't pretend to understand the nuances of arithmancy as you do, but I do know a lot of things that are crucial to the war's movement based on the students here. You may have included some of these things, but I can offer a significantly more complete record."

"Be that as it may, what makes you think your little project is so vital?"

"I know this project is vital for two reasons. First, the reaction Professor Snape had when I showed him the charts last week. Second, Professor Dumbledore set up this meeting. If either believed my work was irrelevant they would have told me so, albeit in quite different ways."

Hermione's heart was running like a rabbit. She needed Professor Vector on her side, but she wasn't prepared to just show her the work without her word that all confidences would be concealed. She hoped that appealing with the proverbial backing of Professor Snape and the Headmaster would offer the sway she needed. The moment was tense to say the least as Hermione tried to hold her composure under the professor's pointed appraisal.

A house elf popped in with their lunch and broke the tension as they both glanced in the direction of the usual "Pop." "I ordered cottage pie and tea." The professor pushed back from her desk, scraping the chair's legs along the worn stone floor. "One of the many blessings of being protected inside the castle instead of fighting on the outside is the unending abundance of food. Have you ever been truly hungry, Miss Granger?"

Whether the change in subject was a positive one, she couldn't yet say, but she went with it. "There was one time when I went camping with my parents and we struggled to work out how to cook on the campfire. Everything was either charred to nothing or raw in the middle. It was pretty miserable. But hunger like I think you're referring to? No, nothing like that."

Professor Vector sat a crock of cottage pie on the edge of the desk in front of Hermione, giving a little wave to indicate that she should eat. Picking up the fork that had been unceremoniously stabbed into the middle of the dish, she used the side of the prongs to pull the golden crust away from the bowl's edges. "I'm very glad to hear it," said the witch as she reclaimed her seat and once more scraped across the floor to gain purchase at her desk. "During the first war, I was on the run in France for six months. I don't think we realize how much a full belly contributes to our ability to do magic. Near the end, I know my wards weren't as strong, my hexes had less impact, and I only got out by the skin of my teeth. It was a good thing I was little more than just a kid then. I didn't know how bad it was."

They ate in silence after that, Hermione contemplating both the question of hunger and why Professor Vector had steered the conversation in that direction. And, although she had eaten breakfast, the crock was empty far too quickly for her liking. As soon as the professor saw that she was finished, she levitated the empty dishes to a conversation table for the house elves to take. "Ok Miss Granger, tell me your secrets. I will keep them under the condition that I will reveal what I know should the circumstances require it."

Hermione thought for a moment, focusing on the tea cup now pressed between her hands. "Professor, that's not enough for me."

"Obstinate girl!" Professor Vector huffed. "We do not have time for these semantics." She huffed again, taking a long sip of tea then replacing the cup to its saucer on the desk. "I get it; you're protecting your friends or whomever, but information is power and the Light needs more right this minute." They sat looking at each other, their disagreement heavy in the air.

She knew that she should relent, that she was the student and not the professor, that her allegiance to the Light was supposed to be greater than to anything else. Still, Hermione could not seem to apologize. The facts were clear and her refusal to accept Vector's condition was petulant and highly destructive. But her heart seemed to beat a steady chorus: "keep him safe."

"Accio faba secretum!" Vector shouted. Hermione immediately noticed that she didn't use her wand. A moment later and she heard the telltale whoosh noise of an object being summoned. It sailed past her head and the professor plucked it from the air. It was a wooden box, mostly plain but with some crude carvings that she couldn't quite make out. "You're right. You're in no position to demand an oath. But," the witch paused, tucking her long silver-black hair behind her ears. "I can respect your desire to be strategic with the information you possess. A very Slytherin move, I might add." She arched her left eyebrow high, silently daring Hermione to deny the claim with her Gryffindor brashness. Of course she couldn't refute the observation. Like most of her fellow Gryffindors, she never entertained that she had the common traits ascribed to Slytherin House. If anything, she felt a kinship with the Ravenclaws and their thirst for knowledge. However, Hermione had done enough clandestine things at Hogwarts—the boomslang skin came to mind—where she used her Gryffindor courage to break the rules, but also some Slytherin stealth and cunning to reach her goals.

"We will not make an oath; rather, we will do something akin to it with no lingering magical side effects. I'm sure you know that once an oath is made, even when the terms of the oath are completed, the binding magic stays with the people involved. Instead, we will use something of my own invention to keep things, shall we say, honest."

Professor Vector opened the box and took out a small object. She held it with her right thumb and forefinger and extended her arm fully so Hermione could get a better look. "This is a Secret Bean. For the most part, it's an ordinary cannellini bean but with a few crucial differences. I've magically made this a vessel that will hold a piece of information within it. It works like a combination rememberall and oath. You will tell me the secret. It will be trapped inside of the bean, at which time I will eat it. The spell connected to the bean performs like an oath, ensuring that if I try to break the terms of our agreement it will make me, at best, nauseated, and at worst, induce violent vomiting. Once the terms of the agreement are met, the bean will inertly pass through my system, leaving no magical trace."

She knew her eyes were as round as saucers, but she couldn't help it. What Professor Vector created was absolutely genius. It seemed she, and her friends come to that, were making oaths left, right, and center. Though they were necessary, they felt horrid, like a little parasite always worming around the body. When an oath was being tested, it drained a person's magical stores and produced a host of symptoms. From the professor's description, the Secret Bean had a definitive shelf life and upset stomach was a clear signal that there might be a violation of the secret. Who would willingly make themselves vomit to share the information?

"I can see you're impressed," deadpanned Vector. "Now, let's get on with this. Take this one." She shook her still extended hand at Hermione's face. She plucked a second one from the box. "One for me. Now then, when I say so, you will tell me your secret. Then I will tell you one. We will swallow our beans simultaneously; it should be taken like a pill. Do you need more tea to wash it down?"

Hermione quickly inspected her cup. "Yes, please." She had never been good at swallowing pills. When she was eight, she had a nasty allergic reaction to some stinging nettles she'd wandered into. Her parents insisted she take Benadryl to reduce the hives, but it was no use. The foul pink pills refused to go down, no matter how much liquid she drank. Eventually her mum smashed the pill and mixed it with chocolate milk. It was not a pleasant memory.

The tea poured, Vector retrieved her wand from an unknown pocket and began muttering a spell over her own bean. The bean glowed a soft, green color. Satisfied that her spell worked she said, "Now, tell me."

With all of the assurances for secrecy that she needed, Hermione didn't hesitate. "Approximately four days ago, Draco Malfoy, who is a Marked Deatheater, became a turncoat for the Light. This coincided with an unexpected tryst he and I had, which has now cemented us in a relationship. Professors Snape and Dumbledore were the first to know and agreed it best to keep Draco's confidence because he'll also work as a spy. Madame Pomfrey and Ginny Weasley are the only other people to know, both under oath to keep the secret. This information needs to remain between you and I and the parties mentioned above. You may only divulge it if the information is a vital matter of life or death."

It felt like it all came out in a rush and if what she had said was shocking to Professor Vector, there was no recognition of it. In fact she appeared nonplussed about the whole thing.

"Very well. Now it's your turn." She muttered the spell again. "I am the inventor of the Secret Bean, and you may not tell anyone about the invention in part or whole until such a time that I publicly reveal it." Hermione didn't know what she had been expecting. It seemed a perfectly innocuous thing to not tell anyone about the Secret Bean. It was an easy secret to keep. And then her brain caught up with her thoughts. That was the point!

The professor waved her wand and whispered different, still unintelligible words. The beans now glowed red for a moment before returning to their normal white appearance. "Swallow it!" commanded the witch. Hermione eyed the bean uneasily, preparing herself to relax and get it over with. She first picked up her teacup and took a large sip of the lukewarm liquid, holding it in reserve in her puffed cheeks. Quickly, she grabbed the bean and crammed it through her tightly pursed lips. Once inside of her mouth, she tipped her head back with a shake, forcing the bean to the back of her throat. She swallowed. Mercifully, tea and bean went down together with no fuss. About half of the time the pill would get stuck in her cheek or on her tongue while the tea was swallowed, and she'd need to spit out the soggy thing and start again, now with the foul taste in her mouth.

"You made that look quite easy." She didn't think she'd ever seen Professor Vector smile, but there she sat with her cheeks high enough to make the crinkles in the corners of her eyes. Clearly her demeanor relaxed significantly. "Ok let's get down to business. Show me these calculations of yours."

With the assurance of the Secret Bean, she dug through her backpack and came up with the newest iteration of the calculations, which included those about Pansy. Vector's mood changed again, now intensely staring at the parchment in her hands. Hermione tried not to squirm in her seat as the minutes ticked by. Like Professor Snape, Professor Vector was a difficult teacher to please. Although she felt she had aptitude for arithmancy, she always wanted to produce work that was excellent. Not only was the witch appraising her skill but also the relevancy that Hermione claimed it had to the war.

Unlike Professor Snape, Professor Vector gave credit when it was due. "As I expected, Miss Granger, this is very thorough. As you insisted, it does cover a great deal of information that I am not privileged to. We shall put our heads together and create the most complete arithmantic predictions possible. Even with all of his spies, He Who Must Not Be Named couldn't hope to create anything so expansive and accurate. Though we don't know who, surely he also has arithmancers working for him. I'll also bet he's arrogant enough to assume that the other students at Hogwarts pose no challenge or threat to him, so they won't be accounted for in the maths. Afterall, they're just children."

It was a relief to hear the professor's affirmation. "Now, let's have a look, shall we?" When Hermione looked at the charts just prior to the meeting, it took her a moment to reorient to the image. With the addition of so much new information, there were more lines, more colors, more everything. As expected, her line and Draco's line were fused together and Professor Snape's ran very closely parallel. Ron's and Luna's lines became closer, as did Harry's and Padma's. Ginny's line, once hovering on its own, was flanked by Neville's and Blaise's on either side. Pansy's line sharply met her and Draco's line several times, indicating that she would engage with one or both of them in the near future. So long as Pansy didn't know that she and Draco were lovers, they could assume that it would always be Draco that she interacted with. Hermione willfully assumed those would be arguments and skirmishes instead of other kinds of encounters.

As before, Voldemort stayed separate from most of the other participants in the graph, occasionally meeting with known Deatheaters, including Professor Snape and Draco. According to Draco's intel, the Final Battle would take place near, if not on, the winter solstice. The graph plotted in accordance with that timeline. As things neared the perspective Final Battle, the graph became muddled. With so many lines screaming to the same point, it became difficult to read and see the nuances between the different potential scenarios. Even so, her calculations didn't yield a definitive outcome from the battle. The lines converged in a tight knot, making the individual colors into an indistinguishable brown color. She hoped that with Professor Vector's input, they could reach some clarity and form plans based on different futures to work toward.

"What a mess!" Professor Vector exclaimed. "Why is everything so packed together?" The witch was exasperated. Hermione was confused. "Proper arithmancy needs room to breathe." She went back to staring at the maths. "Ah! Here it is!" the professor trilled. "You haven't included the kenaz formula to your initial graph spells. In class we don't do anything that requires them, so it's no wonder it's not there. This will stretch the image into a bigger scene so we can really see what's going on. You should be the one to write it in. Do you know what the formula is?"

"No, can you draw it for me so I may copy it?" Professor Vector did just that, explaining as she went.

"Begin with kenaz rune for revelation and knowledge. Then, snug it next to the sign for Jupiter for expansion. Now do the equation for prime 3, standard deviation. That's it." Hermione quickly copied the formula onto her parchment near the very top where the constructions equations were. "Let's try again, shall we?"

Now the graph was huge. Before, the image was about three feet square. It was double that size easily, stretching across the professor's office in such a way that it disappeared through stacks of books and other ephemera dotted here and there. Instead of standing in front of it and taking it all in without moving, she could walk up and down the spectral timeline and examine individual parts in detail. "If you think this is amazing, wait until we merge the two sets of equations. It'll knock your socks off!" crowed Professor Vector. "I can see how closely you're traveling with Mr. Malfoy. It's not quite one line, but pretty damn close. Of course you know that means any change to what is happening between you could cause this whole thing to transform in an instant. If you have a lover's tiff and one of you storms off to something stupid, you could change the whole outcome of the war." Hermione paled visibly. She knew the stakes were high; she well-remembered her shock after their night in the Prefect's Bathroom, when the images changed so radically. It was a lot of pressure. All relationships were tricky at points, new ones especially. Add to the mix that it was between two staunch enemies and rivals, that was a recipe for disaster. They hadn't yet had a knock down drag out row about anything, but it hadn't even been a week!

Lost in thought, she heard Professor Vector tut, tut, tut behind her. "Oh deary dear, look at this. Miss Granger, have you considered what will be happening here?"

She turned and stood next to the professor, following her line of sight to the point on the timeline. Her heart raced and her mouth went suddenly, inexplicably dry. There it was, hovering before her. In one of those moments when Pansy Bloody Parkinson insinuated herself into her line with Draco, there was a bright white spot. And Hermione's line stopped abruptly.