To Hermione's surprise, Potter wasn't fazed. "What's your goal here, Hermione?" he asked, calmly.

"My goal? My goal?" She didn't like the hysterical tone, so she dialled it down a bit. Keeping control of the situation was her only priority. "My goal is to move us - slowly - to the door. Your wand can stay with me." Suiting her actions to her words, she snatched the wand without looking and pocketed it. "Then, my goal is to yell for help without your madness and mind tricks, you disgusting freak !"

"Won't work." Though he predictably flinched at the word, he was still calm. "First of all, that's the one thing I can't allow. It's better to risk dying than exposure. At least that's a quicker way of getting to the same destination. Second of all, you may or may not have noticed that I'm a little … depressed. I don't have anything to lose, now. Third of all, if you just blind me, I have an amazing tolerance for pain and I can still overpower you before you get to my other eye. And if you kill someone with an athame, that's a ritual slaying, and nothing in the world will keep a muggle-born who does that away from the Kiss. You won't even be considered fit for the Veil. Especially for killing an 11-year-old Boy Who Lived and proving once and for all that everything the Dark side says about muggle-borns is all too true. Won't that make a brilliant addition to The Rise and Fall of the Dark Arts ?"

Hermione felt really sick.

Okay, she thought to herself. Being completely mad clearly gives you unexpected advantages in bizarre situations. I can work with this. He can't - can he? - keep me under his thumb forever. With what she hoped was a bit of grace, she handed the lunatic his wand back and slumped in the corner. To her shame and despair, she could feel tears she hadn't even known she was holding back running down her face, which she slowly hid with her trembling hands.

"Now," she heard, "None of that. As I suggested earlier, why not talk it out? I will have to swear you to secrecy, but that shouldn't be a problem …"

Recovering herself a little, she interjected, "And just how would you do that? According to the textbooks - and I've read every single one of them twice - there are, certainly, spells and potions to compel such a thing for a little while, but the only thing that would possibly work long-term would be an Unbreakable Vow, and you don't seem to have a person handy to be our Binder, now do you? Also, it goes without saying that I would never risk my life or my magic just to hear you raving about your sick fixations, so it's a double non-starter, frankly."

To her surprise, Potter smiled. "I still think we're doomed without your special knowledge — okay, not us, per se, but a lot of the others I want to save — but I had forgotten why I really need you. You're as savvy as ever and you're only eleven! Well, nearly twelve, but still…" He moved his arm towards Hermione, who flinched away like a frightened animal and pushed herself further into the corner.

Backing off, Potter tried another tack: "Okay, swear on your honour?"

Hermione shook her head, firmly.

"Fine." Potter ran his hand through his hair, with a tired sigh. "I'll just tell you. If I can't persuade you not to blab, I guess it's on me."

Okay, thought Hermione. It can't hurt to get more information, given I can't run for help.

"First of all," began Potter, "I have travelled back in time spiritually, using a ritual that I worked out with … well, you and a friend of ours you don't know named Luna. Where I came from, we had just missed most of what would have been our seventh year at Hogwarts. We were fighting the Dark Lord Voldemort …"

"Oh, is that his name?" she interjected, unable to help herself. Potter nodded.

"Anyway, not only did the fight kill a lot of our friends and relatives, but no sooner had he hit the ground than his followers and hidden supporters moved to worm their way back into control of Wizarding Britain. We were urged to take our awards and shut up, especially you. It seemed like everything we did was pointless, I mean, the purebloods didn't need the excuse of the Imperius anymore, now that their out-of-control leader wasn't around, making the situation intolerable for the majority of the tiny segment of the population that actually had any power." He paused and looked at her. "Which is why, out of desperation, we tried the ritual. But we could only get enough unicorn and phoenix blood, given willingly I mean, not to mention other requirements, to send one person back."

Smiling, he continued, "But that's where you and Luna came in. We came up with another ritual that would bring one of you back after I got here. Luna said it couldn't be her; it would interfere with her foresight. I don't know if that's true, or she just wanted to give us time together, given we'd finally…"

"Skip past what you're about to say, I am not interested," Hermione interrupted. Potter looked wounded, but she didn't care. Nothing said she had to put up with amorous maundering from a lunatic. Especially, if his story had any truth in it, a seventeen-year-old of-age wizard lunatic, wooing an eleven-year-old schoolgirl. But to expect any sense or decency from a lunatic would be pointless, so she should be as grumpy as possible in hopes it would spur him to do as she said.

"Fine," he said. "Anyway, we collected what you saw in the vials, and added it to the ritual at our end…"

"Wait. Wait." Hermione didn't mind interrupting again. Now, at least, she could say his story was definitely a lie. That probably called for bringing it to halt.

"You said you sent your soul or your memories or something back. That implies, does it not, that nothing material came with you? So how do you account for the vials being here?"

"Well, it's tricky," Potter responded. "Roughly, I had the same runes drawn on my body with the same paste — we designed everything so it wouldn't interfere with the send-back ritual. I managed to find the non-Hermione materials when I came back, a week ago. Then, after I stunned you, I magically extracted the required materials from your body, and using the image of your older self imbued in me by the ritual in the future, I transfigured everything into the corresponding body fragments of your future self. I even recovered the future entries in your diary after I made a Gemino copy. That made it your future self's diary before I ground it up. Clever, no?"

"Disturbing? Yes, definitely," she responded. Then she had an awful realisation. "Wait, if that's true why did you go spare when I broke the circles and ruined the ritual? It sounds like everything you did you could re-do. Meaning, you're a continual threat, right?"

Potter looked startled. "Well, technically, I suppose. The astrological conditions happened to be very favourable today … and getting things like uncursed unicorn blood and phoenix anything isn't exactly easy or inconspicuous. But I suppose you are largely correct." He sighed. "And the answer to why I 'went spare' is that I was Confunded to believe it was my one shot at the ritual. It doesn't work, you see, unless you really believe ." His emphasis on the last word made his point clear.

"By you?"

" Confunded , you mean? Yeah."

Too bad, she thought. If he needed a third party I might have been in the clear.

"All right," Hermione began. "It's time to grasp the nettle here. What would have happened, in your own words, if I hadn't woken up mid-ritual?"

"Well, you would have had your memories restored. And we'd be together. I'd have my Hermione back."

"Restored. Right. Even though I had never been Obliviated in the first place. What a kind euphemism for your insanity. And by 'your Hermione' I assume you mean a grown woman you knew and apparently were infatuated with in … what, 1997?"

"Well, she's you, is the point …"

"She is? You've been back a week, you say. Haven't you already distorted the time stream, especially today, enough that the Hermione you knew won't ever exist in this time? And if she's no different to me, why is she, not I, your Hermione? Hmm? Why are you so desperate to get rid of me and replace me?"

"It's not like that!" he cried, petulantly.

"Oh, I think it's exactly like that. And that's not all you're on the hook for, lunatic. What is your - as they put it - blood status, again? Pureblood?"

"Half-blood, technically. Mum was a muggle-born like you."

"If she's anything at all like me, she's turning in her grave about now. You managed to achieve what even 'Vol de mort' couldn't do — what they gave their lives to prevent." She deliberately didn't pronounce the "t." There was no point in not showing she was fluent in French, she reasoned.

Potter's expression suddenly showed red-faced outrage. Hermione guessed she probably looked smug.

"Yes, you managed to kill the Boy Who Lived off. Permanently. As an innocent undersized schoolboy, too. Congratulations, hero."

"I did not! And even if you want to twist everything into some sick rationalisation that I did, hey, I was him. I was there, and let me tell you, even after getting to Hogwarts, it was not a life worth living. More days than not, I wished I could just lie down and die, actually."

"Still, Potter, you, a half-blood, killed the Boy Who Lived with a ritual. That makes it a ritual slaying. What were you telling me about all that?"

"That you could never prove it. Anyway, if you gave it away I'd end up in the Department of Mysteries, having all my secrets forcibly extracted before they obliviated me so thoroughly I wouldn't remember how to eat solid food. Which, I have pointed out, I won't allow."

"And what I won't allow, at all costs, is another ritual to kill me. I have, to quote your own words, nothing to lose, either."

Potter ran his hand through his hair again. He was starting to sweat visibly. "Look. It's not like that. You're not looking at the whole time-stream picture. And it's not like my young self's memories are completely gone, or I wouldn't be able to blend in, would I? I can consult them … it's like he's a portrait in my mind or something."

"Ah, yes. So after you kill me, I will still be able to be a portrait to serve your adult crush as you two use our eleven-year-old bodies to court and spark. I certainly look forward to an afterlife as a bloody portrait. How can I ever thank you enough?"

She deliberately paused and sipped her mug of tea, which had become room temperature. Fortunately, she didn't mind tepid tea. She eyed one of the pasties in a speculative way. As she said all that, however, she had felt a twinge. It reminded her of the feeling she'd had after she broke the ritual, in fact. She had a sudden suspicion that she couldn't afford to test at the moment. Or could she? The instant she had that thought, she 'felt' another one. Hello, Hermione. The ensuing mental conversation gave her time to finish one of the pasties and nibble on the other one a bit.

For the first time since meeting Harry Potter, Hermione smiled, although tentatively. "Wait one second, Potter," she said. "Two can play at this game, it turns out. Your ostensible reason for needing to kill me off and replace me with your Hermione is that you need her specialised knowledge?"

He nodded.

"Well, good news. Thanks to your aborted ritual, I know exactly what you mean, now. I find a part of my mind is somehow partitioned off, and I detect a personality there, brimming with thoughts and memories. I would normally assume I was going utterly mad, but with you there as a handy comparison, I can see I have a long way to go to get there. You won't have to take my word for it. Ask me something only your Hermione would know."

"Fine. Who did she get together with during the war, and what does she think of him?"

"Ronald Bilius Weasley. And while she doesn't have the hatred and contempt for him you have, which is one of many things she and Luna learned to live with, she admits it wasn't her finest hour. She threw in that you ended up with his little sister for quite a while."

"Ginevra," he sighed. It seemed to have put him wrong-footed, but he added, "Okay, I can see that. God knows I don't hate Ginny, either. It's exactly as she says, it just wasn't my finest hour. Still, I don't regret the thing with Cho Chang, but I do the business with her."

"She says that's okay, as she wouldn't trade away a minute of the attention she got being Victor's date at the Yule Ball, either."

She took advantage of the pause in the conversation to eat a few bites of the pastie. When she looked up again, her smile was less tentative and more triumphant.

"At any rate, your number one reason for murdering me just flew out the window. Your Hermione says she can teach me anything you want me to learn in a reasonable time. Enough, at any rate, to save anyone you could have saved if you had obliterated me. She also points out, helpfully, that if you had come back a bit further and saved Pandora … Ah, I see, Luna's mother … that would have been rather nice."

Now, for the first time, Potter did look guilty. "It made the whole ritual less of a sure thing, and I decided I probably couldn't do much before I got the letter, anyway. Before that, the thugs I was living with kept me on a very short leash indeed." He nonetheless continued, "Still I don't know how I can face Luna. Well, the best I can do now is making sure she knows she has friends now. I think we need to go to Devon, Ottery St. Catchpole, if I can somehow persuade you to trust me."

"You? Never. The old Hermione's mental portrait, absolutely. For one thing, she can't disobey me or lie to me. Two traits one wishes you had, Cultist Potter." Thankfully, she didn't say the thought that inspired, out loud. Perhaps there was a way, perhaps not, that she could turn her Hogwarts situation into a real triumph.

To distract him, she changed the subject. "Is this Luna … Lovegood? That cannot seriously be her name - it's like something out of a Bond movie … hell, something out of Casino Royale - all right, older Hermione, whatever you say. Anyway is she another schoolgirl you're going to inappropriately pursue? Is your undying love for your Hermione subject to two-timing?"

"No, no, she's like a little sister."

"According to old Hermione, that's precisely how you described her to the Weasley boy. Given your propensity to incest , I will take that as a 'yes'."

"Seriously? Take it any way you wish, but I won't be pursuing her that way. Eww. And mocking me when I have lost the love of my life - twice - recently? You are definitely not as nice as your older counterpart, Hermione."

"She says, 'simply more honest, and coddles you less, Harry'." Then she changed the subject again. "Did one or more of the books you took out of the trunk have the rituals you used in it?"

Potter looked confused, and not at all in a mood to be cooperative.

"I mean, you want my help, my trained help. My roving, inquiring mind you love so much needs this information to be satisfied and cooperative. Give, please," she said, holding out her left hand. She figured always having her right hand free was still a good idea with her deranged companion up to whatever insane plan he'd switched to.

As Potter handed her the books, she placed them next to her on the seat. Then she finished the pastie and wiped her hands carefully with a pre-moistened serviette she fetched out of her pocket. Opening one of the books, she demanded he show her the ritual he'd been using. It was the very last spell in the blood rituals section, and she felt extremely triumphant on learning that the very last part of the ritual - the part she'd aborted - included elements of an exorcism ritual. It had been a wild, mad guess, but she'd been correct. She controlled herself to keep from looking at Harry Potter in a speculative way, but she couldn't conceal her exalted mood. Potter looked confused and nervous.

We've already established the rules of the game, thought Hermione. Let's see how much you enjoy playing, shall we?

At that moment, they both heard the announcement that they were arriving at Hogsmeade.

Notes:

Some fan fiction has, e.g., Harry send his thoughts/soul/memories back in time and a few then "bring back", e.g., Hermione, Luna or Ginny. It's usually done with some potion or incantation or a ritual that takes no props and lasts ten seconds. My assumption is that yanking someone's soul or personality from six or more years in the future back to their body in first through fourth year is major magic that would take a little more than that. It's definitely not as simple as restoring obliviated memories - and we're told in the books that that is a very daunting task even for powerful wizards.
This is Hermione showing you exactly how that looks from the other side of the equation. Put yourself in her shoes and imagine how you'd react!