[Rose Pemberton]

The restricted section of the library had become a battlefield. After the very messy incident with the Oozing Book of Ooze Rose was determined to catalogue every book, every scroll and every tome to ascertain its status and make sure it was stored under the proper conditions. For the past two days she'd been emptying shelf after shelf into a pile of neatly assembled storage crates. Thankfully, there hadn't been many members of staff or students in needing anything from that section of the library.

Cleaning up and getting things back in shape felt oddly empowering. Though Rose looked positively ridiculous in her overall, pair of Wellingtons and hair covered by a headscarf, she couldn't deny that the getup was practical. She'd dislodged a lot of dust and grime during her effort and even though she had a house elf to help with the cleaning of the shelves, the work was harder than anticipated. She quietly wondered if her predecessor had ever bothered to take all the books offs their shelves and just give the library a good manual clean.

She dunked her sponge into her bucket of soapy water and worked over the surface of another empty shelf. Sure, the same could have been accomplished by magic, but there was something deeply satisfying about doing this the old-fashioned way. Somehow the shelves just felt cleaner to her once she had attacked them with soap and put some muscle into it. A charm just wasn't she same, no matter what any text books had to say on the matter.

There was also a second advantage to having all the shelves empty. For quite some time Rose had been considering fitting the library with a system of runes to help with efficient filing as well as keeping some of the older and more delicate tomes in a protective field of magical stasis. She'd never quite worked to this scale before, but runes were her thing and she was quietly confident that she could make the heavy enchantments work.

The only downside was that she didn't have a proper arithmantic chronometer and pelorus which would have been helpful in measuring the strength of runes and area of effect properly. Rose supposed that Dumbledore might have some suitable instruments in his office and she could go and ask him later once she she had finished cleaning up the last couple of shelves.

Except, that had to wait a little while. Her arms were hurting again and her wrists were starting to protest all the heavy spell casting she'd been engaging in to transfer the books into their temporary storage.

Returning to her desk in the main section of the library she rolled out her plans for the restricted section once again going over her calculations. "I wonder," she mused to herself, "If I combine these Rhaetian symbols with those old Predennek ones, how many units of magical force will that result in? What was the conversation again? One thirty sixth times the number of..."

[Harold Prendergast]

It had been a couple of weeks since Harold had spoken to Rose, with the business of measurements and whatnot - though he had to admit as the term wore on, he'd had less time to plan out Hamlet and more time had to be spent getting the students up to snuff; owing to the exacting nature of the discipline, he'd arranged for some preparatory examinations for the spring term, prior to the O.W.L. and N.E.W.T. examinations themselves, and a few of the students had wanted - or, rather, warranted - some extra practice sessions.

But he found himself pleasantly surprised with an unexpectedly spare evening, and while ruminating over a particularly fine cup of Keemun, he resolved to visit the library and look up that tome on Tudor-era arithmantic research that he'd heard about.

The library was in rather an unexpected state of affairs; Harold could muster nothing more than a surprised, "Well..." upon seeing the place, with all the shelves stripped bare of their literary residents - though he couldn't deny how wonderfully clean all the shelves were. It was as though a fresh coat of paint and varnish had been laid across the place, though it smelled considerably less awkward.

As he approached the Restricted section - wondering if he should find any books on any shelves there, like as not he wouldn't, he found Rose muttering to herself - one thirty-sixth times the number of... and he'd vaguely heard the words Rhaetian and Predennek, and the calculation just came to him.

Part of him wanted to say nothing and just let it pass, but a larger part of him wanted to help.

"One thirty-sixth times the Phi quotient of the runes' force, plus thirteen - I believe that's the formula for converting Rhaetian to Predennek, though I must admit that, well, it has been a while." He smiled, warmly. "I must say the shelves have never looked so clean since I've been at Hogwarts - even as a child."

He had a think for a moment, before sort of just speaking to himself. "Conversion of Rhaetian to Predennek... calculating the arithmantic outflow of the sympathetic union... I'd want a chronometer for that." Then, as if snapping himself out of a daydream he looked at Rose. "Would you happen to be in need of a chronometer? I have one up in the lab that I was showing to my class. I can pop up and fetch it if it would help."

[Rose Pemberton]

"Yes, yes, that's it," Rose confirmed as a familiar voice spelled out the equation her mind was looking for. "Except I think I'd have to slightly modify it here accounting for the many arcane fields present in the environment. There's a lot of unbound magic floating through the halls of this building as well so it would be wise to build with a bit of tolerance so an accidental magical discharge doesn't immediately trigger a reaction. I was going to have a measure and see if adding a rune of stability into the mix would help matters, but I don't know if I want to use Predennek for that or switch to Futhark, which of course throws another layer of complication."

She looked up. Had it been anyone other than Harold Prendergast listening to her ramble, they'd have probably not understood a word she said. Except, of course, the man next to her just seemed to nod along with mild interest. A chronometer, yes! "You and me both, my dear Hal, you and me both. Alas I don't own one and they are prohibitively expensive. I was going to ask Albus to borrow his or maybe work around the issue. According to Cowell's theorem,..." she stopped. Half-listening she'd happily chatted away without taking in the full meaning of what had been said. Had he really just offered her the use of his instruments? How kind.

"Ah, um," she stuttered awkwardly. "I wouldn't wish to impose. Don't you need those for your research?" Given past experiences the last thing she wanted was get onto the wrong side of Harold Prendergast again. She wouldn't have gone as far as to say that their friendship had been repaired, but they were doing better around each other these days. Working together might throw a spanner in the works. On the other hand she could really do with that chronometer.

"Anyway, I don't imagine you came here to talk to me about rune conversion calculations. Is there anything you're looking for? Sorry for the state of affairs here. Should only be a day or two longer until things are back to normal. The place just needed a good clean and I figured it was as good an opportunity as any to add some wards, protection and runes to create favourable conditions to store these old tomes in." She gestured in the general direction of the crates holding the particularly fragile items she was the most concerned with.

"And I guess... if you have time... maybe some help would be nice. I'm also short a pelorus."

[Harold Prendergast]

"Well, as you put it, no," Harold began, taking is glasses off and polishing them with his tie, "I may not have come here for a discussion about rune conversion calculations - but providence rather clearly had, well, other ideas."

Glasses back into place, he took a look at the shelves as she'd gestured. They really were the cleanest they'd been in years, and the more fragile of tomes could certainly benefit from some charms, wards and general thaumaturgical support - even magical tomes are not immune to the wearing of years.

"What I'm looking for can - quite honestly - wait, it was mostly some academic curiosity on my part to be satisfied rather than any active research. And to be honest, after the letter I received I have been... less inclined to spend so much time in the lab, trying to unravel a mystery that didn't wish to be solved. It has given me more time for planning for lessons, if I can be candid on the subject." A wry smile played across the corners of his lips.

"As for a chronometer, I can absolutely furnish you with one, it's not currently in use in any experiments. As it happens, the only reason Hogwarts has one currently is because I rather needed one for some demonstrations and a few experiments I had intended to carry out, and I applied for one through the education budget. Dumbledore agreed but it only arrived recently."

Harold took a few moments to study the shelves and creates with books in and do a few quick mental calculations. "I should definitely bring the chronometer in; your assessment of unbound magic is spot on, I should say, and having some way to measure the potency would be useful. I can also see if we have a pelorus in the arithmancy department but it's not something that the Minstry currently has on the syllabus. Though the arithmancy department is considerably older than the curent syllabus so there might be one tucked away in one of the storage trunks... not everything in this school is entirely catalogued."

He pondered for a moment. "If I'm already making a trip up to the arithmancy department, is there any other equipment that might be of use? Nothing is quite coming to mind but the use of runes is something I am afraid to say I am rather rusty in."

[Rose Pemberton]

Something Harold wasn't knowledgeable in. Rose raised an eyebrow, as if to say really. Whatever their differences were or had been, she'd never for once believed that he hadn't read at least half a dozen books on the subject. Harold always had something smart to say and though he always tried to do so in a modest manner, Rose wasn't sure if that was one of his more irritating or more endearing traits. Perhaps, both.

She let out a faint sigh. "Truthfully, I could do with a full suite of instruments, but I am just a librarian and probably shouldn't ask. What if one of our more senior colleagues needs the kit? I would really rather hate to get in the way of anybody who needs the equipment for something more pressing. I think I can do most things manually here in the library. Runes, quite possibly, is about the one thing I am halfway decent at."

A thought suddenly popped into her mind. "Err, have you heard anything about how the search for new faculty is going. Dumbledore mentioned divination as well as runes being vacant next term and I was thinking about..." she trailed off as she felt a serious blush coming on. What was she doing mentioning all of this to Harold. The man would be the death of her. All it took was a chance encounter and here she was again, talking about something quite personal.

"Err, sorry. Never mind." She felt embarrassed even though she hadn't brought her thought to conclusion. "Just whatever you can spare from Arithmancy would be nothing short of amazing. It'll make the work so much faster and I have another project to be getting on with as well."

[Harold Prendergast]

"No need to apologise, rather nothing of the sort. On the matter of equipment, I am certain that there are no experiments currently underway - well, you see, I pass the entrance of the classroom on my way to and from the Arithmancy classroom and of the times I have looked in, I found nothing in progress. In fact, the classroom is quite vacant."

He starting polished his glasses absently with his tie. "I have looked in, you see, as there have been a few questions raised in some of our recent experiments that I believe have a connection to some of the runic transcriptions of tales relating to Ragnar Lothbrok, or possibly Lodbrok, I'm a trifle rusty on my reading of Thurisaz and, frankly, my Elder Futhark is as active as my elder Prendergast - that is to say, not at all." He smiled at his own little joke about his father. "I looked in to see if I might borrow some of the syllabaries kept in Classroom 6A's storage, but no-one - not even Dumbledore - appears to have a key."

Placing his glasses back firmly on the bridge of his nose, he looked at Rose. "Dumbledore has wondered rather for some time if the chests are, well, magically enchanted, waiting for someone suitably attuned to working with runes to open them. Perhaps you might speak to him about joining the department? In the meantime, perhaps we should head up to the Arithmancy classroom and collect things - now would be a rather fortunate time in between classes."

Harold gestured in the direction of the door with a polite smile.