A/N:

If you haven't read the Temporal Beacon yet then I'd suggest not reading this one-shot either because you'd very likely be just spoiling yourself the fun with willyolioleo's story.

–Also, don't expect any action from this story, it's intended more as a world-exploration thing.

• • •

"Harry, don't try to apparate onto a moving train, especially not before we've done the blood runes!" The sound of Hermione's voice calmed him down considerably.

"I won't. As for you, Hermione, don't try to walk backwards in front of moving staircases," Harry shifted to a sitting position next to her.

"What?" Hermione blinked in confusion, then started to get frustrated. "Harry, I'm not joking. Something serious happened…"

"Yeah, you told me all about how I killed myself apparating onto a train. While you were doing that, you fell down a flight of moving stairs."

Now she looked annoyed at herself.

"Okay, you are telling me in details how that managed to happen before we exit the Chamber."

"Should be easy enough. You were telling me about our brilliant idea with Hogwarts Express while we were on our way to the Room of Requirement. You were too busy blaming yourself for my death to notice the moved staircase, and I was too busy trying to defend you from your own accusations. So you managed to fall down to your death and I barely managed to not do the same while trying to rescue you. Quite–" Harry was surprised at a sudden expression of fear in her eyes "... fun that was."

Hermione was silent for a while before answering.

"From now on, we should start analysing our latest cycle before moving on with the next one." There was a hint of fear in her voice too.

"I guess adding that to our summer's to-do list will not be enough?" Harry looked at her apprehensively. Why was she so afraid all of a sudden?

"No. We should also start additionally using the Chamber as a mid-dimensional break area of a kind." She leaned a little back from Harry and tentatively looked him into the eyes. "Rearrange our memories here, analyse everything that happened during the latest cycle and only then move on with the next one by resetting once more."

"What is it, Hermione?" Harry was concerned with her reaction. "We both have had died before already, so I'm guessing that's not what got you so worried?"

"No, but let's talk after the memory organisation part. I'd like some time to think it through first."

"All right then. Shouldn't we make the runes first too?" Though of course if they are just going to stay in the room, it may not even be necessary. The original timeline had no major disasters happening to Hogwarts during the next months, and thus they should be reasonably fine to be resetting via rune tablets alone.

"Not if the only thing we do is just stay here." repeat Hermione his own thoughts "Besides, it seems like the regular grounds of Hogwarts can be more dangerous to us than a Secret Chamber created by Salazar Slytherin. If we ignore the basilisk, that is."

They both grew suddenly wary of the dead venomous snake and of the protruding teeth in its half-open mouth.

"I'll be starting with my memories then. Please transfigure a blackboard if you're finished first." Hermione nodded. Harry was actually starting to like the idea himself. It was similar to Quidditch after-practice sessions, during which his team tried to point out and discuss all the strengths and weaknesses that they've managed to notice during the session. Or to the weekend trainings with Moody, for that matter.

"After we're both done with our own memories, we can also start synchronising them with each other through Legilimency." Said Hermione before sitting down again, her legs crossed, and closing her eyes for meditation.

Harry admirably looked at her cute posture for a few seconds before starting to submerge into a meditative state of his own. During his previous mind-organising and Occlumency sessions he'd gradually developed a methodology of sorts that made arranging memories much easier for him. He was visualising the flow of time as a horizontal timeline ('Did you know, Harry, that based on their cultural background wizards can not only write, but also think in different directions? I should've picked up this author much earlier, the minor details he provides draw an amazingly accurate picture on differences between cultures.') ... Right. Focus, Harry.

Since their reset point was currently on June 30th, somewhere near 9:00 AM, his timeline started at June 30th also. He realised that it would possibly prove itself a little inconvenient later on, when they'd eventually manage to travel far enough to graduate or leave Hogwarts, but for now it provided a nice template for a typical school year. Each horizontal line represented a year, and each next year's line started "below" the previous one. Each line was also divided into scales for quarters, months, weeks and days—though it was much harder to visualise the day and week marks then the "larger" month and quarter ones. But nevertheless, when he was working on memory organisation it helped to "walk" along the currently relevant timeline, "fish" for important memories for the given period and arrange them into a coherent string, not neglecting to additionally mark uneventful time periods so that no gaps were left open.

This time too he moved from their somewhat hectic beginning of the last long cycle and continued sorting things out until eventually arriving at his "guesting" period in the Department of Mysteries. There wasn't much that could be done with it however, so he just assigned the whole section from March 11 to April 28 to the little DoM memories that he had. It felt like he was reviewing a period of being comatose. Because of that large skipped section he'd also managed to complete his organising session faster than Hermione.

Not wanting to waste any time just waiting for her, and remembering his own request towards her, he transfigured a blackboard from a wall section that now, after the reset, was a rough dark granite again and started thinking about mistakes that they've made during their last "journey".

Well, he managed to get captured by the unspeakables, as the open gap in his timeline helpfully reminded. But it wasn't like he could defend against such an enemy, and he never even heard about such powerful compulsion and memory techniques until having to experience them himself. So however unpleasant his feelings about this were, the whole thing wasn't exactly his fault.

What was his fault though was how he exposed his Animagus form in front of the whole magical population. That was one more reason for Dumbledore to be suspicions, one less hidden advantage for him and Hermione, and one potentially lingering trial subject if he'd have somehow managed to piss the Ministry off. And all that for only winning one of the tournament eggs. He easily forgot what should be prioritised when he was in the middle of a cycle, it seemed.

Speaking of mixed priorities — it looked like there was a disturbingly high amount of people who could dismantle the glamour protections placed on their runes. Last time around nobody got enough time to use it against them, but if they eventually manage to stay longer inside cycles, the purpose of their runes could potentially be reverse-engineered. Which, in turn, could possibly bring real risks to the meta-nature of their travels.

He wrote "Things to keep secret" on the top of the board and listed "extra abilities (Animagus form, fumation, and Apparition)" and "runes (require better protection)" under it. Then he also added "Things to stay unnoticed from: DoM" on the next line.

By this point he started wondering if Hermione's mental tidying up wasn't taking too long. Turning to check on her revelaed that she had, in fact, finished her meditation. Although she still had a little... meditative quality to her look.

"Hermione?" did she learn this from Luna?

"Yes, it felt nice watching you think." The look in her eyes returned to normal. "I was getting concerned about rune protection too—especially with the unspeakables getting involved the last time around. Unfortunately, they are way out of our league at the moment. And I don't know what can be done against powerful artefacts like Moody's eye either."

"Maybe we should just try to stay away from the former and befriend the latter for the time being." He was not liking the risks that presented themselves with the new, bigger predators set loose. On their penultimate cycle Moody was not so suspicious of them. "Do we have a chance of getting him on our side against Dumbledore?" There was an equal chance of just antagonising the paranoid auror further by such an attempt, he thought.

"I don't know." Hermione too looked concerned about how many new problems were starting to reveal themselves. "We can try freeing him from Imperius again and then asking for a unique piece of information that will prove to him our good intentions in case of him ever "forgetting" us, but will he give something powerful enough to work against Dumbledore? When he was training us he said that as an auror he was aware of the necessity of sacrifices in some cases. But he also made a point about how such a sacrifice must be voluntarily offered. Perhaps we should confront him after Dumbledore sets your death plan into motion and Snape is sent with the mission to Voldemort? " She contemplated the idea for a moment and then made an abrupt shift to another subject. "But there is a more important thing that we should be thinking about. She approached the board, and after transfiguring a piece of chalk for herself added an underlined sentence under the already existing list: "Infinite time loop entrapment."

"Is this what made you so scared after I mentioned you dying?" Harry asked after thinking for a brief moment to himself.

"Yes. We have been extremely reckless on our last two cycles, and I don't even know if we would doom only us if we succeeded to get us both killed or the whole world in a never-ending loop that stretched for less than half a day—even though the latter seems unlikely. Our top priority after each awakening should be placing the body runes at least on one of us. And we should also spend a cycle or two investigating all potential fatal risks for us that are present in 30th of June, 1994 and around Hogwarts and its premises."

"I understand, but would it be really that bad? You wouldn't necessarily misstep the moving staircase on each cycle, would you?" Harry couldn't tell if Hermione was being too careful as she usually was or if the potential risk was indeed that severe.

"Since I have no memories of how exactly the incident occurred, I can't also make estimations about it." Huffed Hermione. "But nonetheless I have never explored how entropy practically affects alternate universes and if they ever so slightly change because of it over time. If there is any difference between different cycles, we may have a very small chance of eventually getting unstuck from the loop—possibly not even realizing afterwards what was happening with us for a very, very long range of cycles. However, even in that case I'd rather not be risking everything when we can simply prevent it from happening by just being careful and cutting the runes first."

"And how would you be exploring the said effects if you wanted?" Harry slightly tilted his head with an interest. The realisation about the grave danger was missing him for some reason. He felt more curious about it than alarmed, even though he understood what Hermione was warning about. "Provided that we do take care of our protection, of course."

"Well, we could find a specific event with a random outcome—for instance in some sports events they toss a coin to determine which side will be opening the match—and check in several different cycles whether the openings are always the same or not. Otherwise, if we'd manage to learn a spell that "freezes us in time" while the rest of the world keeps moving on, we could also freeze ourselves in the chamber in several cycles for significant amounts of time — for hundreds of years perhaps, or even thousands—and then compare the futures to see if the accumulated small changes result in bigger differences over time or not." Hermione stopped to draw a breath. "But like I said, that should not be currently among our priorities, even if it is a very promising subject for research."

"Right, then... we cut our runes first. Anything else that we should be aware of in regard to... 'infinite time loop entrapment'?" Harry asked cautiously.

"Actually, since our memories and our current state of mind seem to be properties of our souls rather than bodies, being captured becomes much more dangerous to us than being outright killed. If someone manages to capture even one of us for a long or intensive period of brainwashing, potentially they can manage to condition the captured person to be ready to kill the other one and commit suicide afterwards. In such a scenario too we can get easily trapped in an infinite loop, if prior to that there were no preventive countermeasures implemented by us." She started writing something under the already written sentence of "... loop entrapment" but then stopped. "I think we'll need something better than a blackboard for this." She headed towards her book bag to get a few pieces of parchment.

"Can you devise a spell similar to Calentempa to show how many cycles we've been through so far?" Harry remembered their first awakening after Beacon's activation. "It will not protect against brainwashing, but if we wake up and notice a missing cycle we'll at least know that something went very wrong on the last travel."

"That can actually prove to be very helpful, Harry!" Hermione was almost done transferring the blackboard information to her own notes. "Ideally, I'd like to create artificial 'judges' from our personalities of the last two cycles or so but it will take for me at least 8–10 years of research to even tell if something like that is truly possible. And regarding the spell that you've mentioned, I can at least make something like that based on runes. It will take only minutes to make it, actually." She headed to her book bag yet again, this time for the Runes tool-kit and the last remaining sandstone tablets.

"What do you mean by artificial judges?"

"At the end of each long-lasting cycle we wake up more or less different then we were before. If we can create 'guardians' in our minds based on our personalities right after awakening, they can function as 'testers' of each new changed personality that awakens after the last cycle. Such judges will be able to decide whether the new one is to be trusted with control or not. But as I said, it's just an idea that I've read about in a book that was referenced in the Restricted Section and I don't even know if it's really possible to achieve." She looked up from her work for a moment "And there is one more countermeasure that we can implement but I don't know if you'll like it."

"Black magic?" The gravity in her voice didn't escape Harry.

"No, but... well, I think I can connect our runes to each other so that each of us is capable of terminating both our lives through 'safeword'-activation."

"And that can be done without black magic?" Harry asked disbelievingly.

"Blood runes are not a completely forbidden branch of magic. And yes, it can be done without involving any 'classic' black magic. One could say that it's similar to how regular spells and charms work. I can banish someone into an abyss, make an explosion on someone's body and so on, but all that will still be only an inappropriate use of an otherwise legitimate spell."

"I see... I will think about it before giving an answer, all right?" Something like that could eventually become necessary for them but it sounded too extreme nonetheless. "For the time being let's just stick with the more simple options. Like the one you are preparing right now."

"I am done preparing it, actually. Want to come closer before activating it?"

"Yes, of course I do. How does it work? Does the Beacon itself have its own memory or what?" Now that he had the knowledge of how the runic magic worked, it was much more interesting to him than he could've imagined before.

"Something like that, yes. As long as the installed combination is intact and continuously working, it is capable of keeping basic statistics about its own functioning. Gathering that data is actually much easier than sending us back in time—that's why the tablet took so little time to finish." Hermione activated the tablet with the final version of her design and there was silence after that.

Between them, suspended in mid-air above the tablet, was dimly glowing the number 57.

• • •

End notes:

– In willyolioleo's story the Beacon only serves as an anchor point, so if they both managed to die without bearing the runic protections, I guess they would not be returning to the checkpoint—even without their memories. However, there could be some unaccounted phenomenon that keeps bringing them back even without their memories. This story is essentially based on a premise that such a phenomenon exists and that Hermione has recently discovered its existence.

– I wanted to mention a few more things but it was getting too large for a one-shot, so I decided to finish it this way.

– Hope you enjoyed it, and please write back if you notice anything wrong. English is not my native language, so I'll be very glad for any feedback provided.

– Harry easily transfigures a blackboard because in Temporal Beacon transfigurations are done much easier than in canon and some other stories.

So if you haven't read the Temporal Beacon yet then I'd suggest not reading this one-shot either because you'd very likely be