The librarian is tilted so far forward into his current tome that he looks to be attempting to merge with it. As Sugira stands, the man snorts and turns his head in his direction, though his eyes remain on the page. He coughs, "Sara," he calls, "Get me 'Permanence', by Dauntless. Cursed elitists have no idea what they're talking about," the last part is grumbled into his beard. 

"I'm not Sara," he says.

The man starts, raising his head from the book to squint at him. After a moment he clears his throat, "That does seem to be so," he agrees. He scrutinises Sugira for a long moment, and then turns towards the shelves, "Where is that girl?" He mutters, then, quite against the spirit of librarianism, calls, "Sara!" Into the still air of the library.

Listening closely, one might be able to hear the sound of something hard hitting wood in the back. Seconds later a young, feminine voice shouts, "Coming!" 

"Don't shout in the library," Kelka shouts in return. Then he turns back to Sugira. "How can I help you, young one?" He asks mildly. 

"What do I do with books I've read?"

He hums, eying their vividly coloured covers, "Elementary Principles, hm?" He says, "A good choice." He glances back towards the shelves, "Not to worry, not to worry; my assistant will reshelve them for you." 

He nods. "Are there similar series, or things on interactions between magic types?"

A young woman creeps out from between two of the rightmost shelves, a large tome clutched in her arms. She blinks curiously at the sight of another person in the library this late. 

"Magic types?" The old man repeats, "Well, there's plenty of books on the interaction between the eight colours, if that's what you mean by 'types'?" 

 "Did you need something, Master Kelka?" The girl asks. 

"Ah, Sara, yes. Where were you, child? Well, nevermind, I need a copy of 'Permanence', by Dauntless."

Sara blinks, nods, and disappears into the stacks. 

Kelka turns back to Sugira, "As for series such as that one there, you won't find any so simple yet so useful, if I might flatter myself, but there are any number of compendiums of imprinted spells to be found in the Compendiums section."

"I'll stick to this series for now, then. And which books on color interaction are good?"

The librarian hums, tapping the table in front of him in thought. After a moment, he heaves himself to his feet and makes his way towards the 'Mana Studies' shelves. He stops at the third bookcase in and runs his finger over the spines of the books there before tugging one out.  

"Here we are," He says, "'Compound Spells, First Tier' is a good choice for beginners." He moves two more shelves down and pulls down another, "And this is 'Mana Interactions', which covers both natural and guided interactions." 

"Master Kelka?" Sara calls.

He passes the books into Sugira's arms and strides back to the front. "Ah, thank you," he tells her, "And what were you reading about?" 

"Ancient Machinery, and how it works, sir." 

"A fascinating topic! And it ties into my current project, come, let us have a look at 'Permanence'; no Machinery could be built without an understanding of the topic, after all." 

He takes the books, thanks the man, and settles in to read 'Mana Interactions.'

'Mana Interactions' is not so organised as the series Sugira has been reading, but it does cover the promised topics. 

According to the book, there is mana permeating everything in this world in amounts so small as to be imperceptible. The landscape contains mana which is related to it - such as lakes having high concentrations of Water Mana, or forests breathing Life and Earth. It also states that high in the air the mana of that type thickens dramatically, and that the stars, sun, and moon are effects of the high concentration of Illusion Mana which pre-Seal resources suggest is there. 

The book discusses the Mana Veins, thick rivers of unaligned or coloured mana which course through the earth, the outer layer sometimes coming close enough to the surface to create Mana Wellsprings, such as the one Sanctuary is situated on, or breaching it to continue into the air, as the two wellsprings at the ulimate north and south of the world are said to. 

When veins of mana surface, the site of the wellsprig often becomes affected by that interaction. In the same way that a forest will breathe out Life and Earth, a cross of these types will create a great forest of its own. An example of this exists in Cialin, in the form of the Tuvek Forest, which stretches across an eighth of the country and consists of trees so wide and tall that man settlements are built inside them and in the canopy, rather than on the ground. 

A less common but more dangerous category of this is the illusion and water wellspring in south Cian. The site is a misty bogland filled with illusionary figures which tempt onlookers after them and to their doom.

The book states that most wellsprings are covered by pre-Seal structures, which harness the mana there the same way Sanctuary does. 

It only briefly switches to the topic of guided interactions, stating that much like the natural world contains mixes of different colours of mana, a mage may make use of interactions as well. A mixture of Life and Earth mana to convince a seed to grow, a blend of Illusion and Fire to create a light which does not burn, and many more. 

Hm.... Sounds like if it interacts with his magic system at all, it'll interact strangely - he'll need to test out how elemental cantrips, and cantrips from different fields, interact with their spells.

Sounds like it. 

By the time he finishes the latest book, Kelka has been reabsorbed by his work. His assistant is working with a little set of stone and metal tiles, carefully carving into one of the metal ones with a stylus of the same material, which is covered in little carvings of its own which glow a cheery red-orange.

After a moment she lifts the stylus and sets it down, the glow fading as she does so. She looks up from her work and notices that he's finised the book.

 "Need anything?" She asks, her voice quiet in deference to the Master's focus. 

Just as quietly: "I'm trying to figure out how a different magic system might interact."

"A... different magic system?" She repeats, uncertain, "I'm not sure. I suppose it depends on what kind of magic this other system would be?" 

Well, he'll explain wizardry as best he can. It draws on arcane energies, the source of which are unknown, and channels them through the caster. You have to memorize specific sequences to shape the channeled energy into specific effects, and channeling burns the memorized sequences out of your mind.

Sara takes it in with interest, "That sounds fascinating," she says. "Maybe more limiting?" She speculates, unsure, "But if you can only cast with patterns, I guess there wouldn't be unstructured mana accidents." 

She pauses, fiddling with one of her tiles, "Could you make permanent effects with it?" She asks, holding up the one in her hand; it's one of the ones made out of the strange black metal, a symbol carved into it - ℑ.

"We can have accidents if we use the wrong pattern, but if you follow instructions and aren't in spell-development that's rare. There's a permanency spell, that's difficult to learn to do, and methods for enchanting objects, that's a bit easier."

"Permanence and enchantment mean then same thing, for us. If you want a permanent effect you have to enchant an object to hold it. But, you wanted to know about how they might interact, right? I don't think there's any information on the topic - if there's any other kind of magic, it's not in these books, at least. Would it be safe to experiment a little? If I held a benign enough spell, maybe water ball or something similar, and you cast something on it?"

"Experimenting should be safe."

She grins, reaches out a hand, palm upright - and then pauses, "Um. Maybe not here, though. In case of explosions, or anything along those lines. The training rooms aren't far away?" She pulls out a small drawstring bag which she sweeps the tiles into, and then pockets it and the stylus she was using earlier. 

"Somewhere more amenable to explosions does seem good. Training rooms work."

She stands, glancing over at Kelka, who is dozing into his notes - he'll be in for a rough morning, but there's no getting him up when he's asleep, so she just tugs one of the cushions off a chair and swaps it for the book, closing it on a ribbon to mark his place. She leaves the books Sugira was reading in a neat pile on the table, so she'll notice them first thing when she gets back, and then leads him out of the library. 

She quickly heads into the servants' halls, and then out into the water gardens again. The indoor training rooms have their own building at the south end of the palace, the outdoor fields stretching out beyond that before hitting the back wall. She goes in through a side door, tapping the access disc with a thread of mana to open it for them. Peering into a few rooms, she skips three occupied ones before pushing open the door to a fourth and heading inside. 

The room is 30x30 - all the ones in this side of the hall are. There a long bench along the wall with the door, and mirrors on the two side walls, and the far wall comes out to form a counter. 

"Most people practice Earth magic outside, or in the courtyard, but these rooms work for everything else," she comments. "Anyway, I can hold a water ball for a while. Just let me know when you're ready!"

He mentally flips through his spells. "Ready."

She reaches her palm out again, and draws up a thread of water magic. Pulling it up through her palm, she recites her incantation - just 'water ball' - and it settles in her palm as a lightly glowing sphere of water, rotating gently. 

"This one is pretty safe to do just free-casting, it's pretty hard to mess it up in a dangerous way," she mentions, "Making it a spell just takes less focus." She nods to him, "Go ahead."