Mary and the wizarding party entered the library entrance hall running. Mary stumbled on the doorstep and fell to the floor, panting. Others weren’t doing much better, except for Kevin, whose excitement still kept him upright and casting. He raised both hands to the sky (currently obstructed by the stone ceiling above), and with an incantation of “Ouy lliw ton ssap!” slammed his staff vertically into the floor.

“Shhhh!” A loud hiss rang out in the corridor. Mary really hoped that the academy wasn’t using any gas pipes - a leak could prove immediately fatal with the amount of fire around them.

A giant stag made of slivery flames shot out of Kevin’s staff’s and roared at the spiders that were still pursuing them. A lightning bolt struck the animal’s antlers, causing the electric arcs to jump back and forth between them, increasing in frequency until they formed a vortex of an almost constant thunderstorm. Everything grew quiet, and even dumb too-many legged fellas stopped, seemingly getting the message. A couple of seconds more, and an explosion of silvery flames and thunders erupted towards the fell beasts. The wave of blinding bright wall reached them… and went right through, without doing causing them any harm.

“Damn, I thought I got it right this time,” Kevin whined, accompanied by uncomfortably loud clicking of spiders surprised by the flashiness of their future meal.

“Oh, for quack’s sake,” Danielle cried, raising her staff. “Teg eht kcuf ffo ym nwal!”

“Shhh!” The familiar hissing sounded again, somehow louder than the ongoing battle.

A blazing sphere of iridescent light flew from her weapon straight towards the tunnel, and in a single explosion, all the spiders were burrowed under the rubble. It took almost a minute for the broken stones to settle.

“Shhhhhhhhhh!” A roaring voice blasted behind Mary’s back as she rose back to her feet - which was much more awkward than usual due to the overgrown and underseen tome she was carrying. A shrivelled, old woman in half a century old dress glared at them from above her clipboard. So, at least it wasn’t a gas leak after all. “Quiet! This is a library!”

The woman’s booming voice made Mary curious whether this part of reality had some reverse cigarettes or something like that - there was no way that a woman this old could have so much breath power running on her natural biology alone.

“The youth these days, no respect for elders, no proper savoir-vivre, I swear, one day-”

“We're sorry, Ms Yellbender,” Cesius whispered, twisting his face in an overdone smile. “This won’t happen again. I’ll make sure of it.”

The old librarian stopped the yelling and switched to murmuring swears under her breath, evidently mollified. Her eyes darted between the kids, seeking prey.

“Do you kids want to borrow something?” she asked, failing to find any obvious infractions.

Melanie’s face blanched, and so did Cesius’s. Mary couldn’t see Danielle’s under the hood, and Kevin… well, he was Kevin. In a sudden epiphany, Mary moved the invisible book to a one-hand grip on her side and tried to act naturally.

“No, Ms Yellbender,” Mary said, trying to ignore the tension in the air.

The woman looked at her, then at the rest of the team, and with a snarl told them to get lost.

“That was close,” Danielle said as they left the building.

“What was that?” Mary asked.

“What do you mean?” Cesius asked. “It was the library. You are from a reality where libraries are a thing, aren't you?”

“Yes, I... are there other ones?” Wait, of course, there were - the library doesn't sound like a basic building block for the universe. “Anyway, I meant that woman. What was she doing there?”

“It was Ms Yellbender, Mary. She’s the librarian,” Kevin said.

“But, why had she appeared right now? Why wasn’t she there before?”

The others exchanged a look.

“Mary…,” Melanie trailed off. “She’d always been there. Are you feeling alright?”

The heroine in question assured everyone that everything was perfectly alright, despite feeling exactly the opposite. They all walked in silence for a while, unless you count a random flame crackling around Kevin's staff from time to time. Mary couldn’t stop thinking about the woman. She should have passed by that woman three times already - surely, she would have noticed someone like that? But Mary couldn’t deny seeing her this time either - and the wizarding party didn’t act like the librarian was a new addition, and the desk with various documents she seemed to own didn’t look like a new thing either. Was Mary going mad? Well, madder than she should, given the circumstances?

It was evening already, and the tired sun reflected off the Tanuor statue’s curves sent random spots of concentrated light all over the path, almost melting some of the stones. They passed the arena from the selection ceremony and the upside-down glass pyramid before Danielle called for a stop.

“Ok, I need a moment with Mary alone. Off with the rest of you, and make sure Kevin doesn’t burn down anything too important.” She waited for them to leave and turned towards the remaining girl. “Do you think you can carry on on your own from here on?”

Mary glanced at... through the invisible book in her arms. “Yeah, I think I’ll think of something. Thank you for the help.”

Danielle sighed. “I’m doing this because of Margaret and Hans. They used to help us in the past. I’d offer you a place in my party in their absence, but we’re already four. Maximum party size isn’t strictly in the rules, but anything from five up is frowned upon, and we don’t need that kind of attention, not with Kevin around. I’d gladly help you more, but this already looks like a major issue, and those are supposed to be solved from within the party. I hope we won’t get too much trouble for that little stunt…,” she trailed off, glanced behind, and sighed. “Kevin can really be a handful sometimes, but I'm his leader. I'm sorry, but my party comes first.”

“Well… at least some parts of what you've just said don't seem to make a lot of sense,” Mary said and cursed softly after Mossie hit her with a paper that confirmed her two-hundred dollars fine. “But yeah, I get it. And I am grateful, really. Should you ever need my help, you can count on it.”

The other girl nodded, and after shaking hands, they each went their own way - Danielle towards a column of smoke coming from where her party had just headed, and Mary towards her dorm, where she hoped to crack the book’s secret.

It didn’t look good. The sun was long gone, but despite skipping dinner, Mary made little progress on the riddle.

Her fingers could feel the book alright, and it could clearly hold the objects she placed on its back. She could turn individual pages, but whatever made the book invisible was just too perfect. There wasn’t a single visual hint that anything was there - no weird specks of illumination, no distortion, no inconsistent shadows, no nothing.

Feeling the uneven surface of the paper, Mary tried spilling sand with the hope that it would shape itself into letters, but all she got was some random dots and a lot of sand to clean from her desk. She tried looking through a page at the sun and at the lamp. Then tried to examine the shadow (or rather, lack of thereof) cast by a single page. She even tried pouring a few drops of water on the corner, but the liquid simply vanished on contact, leaving a wet spot on the still invisible page.

Desperate, she repeated the deed with ink, but to her relief and further despair, it vanished just the same, leaving no lasting damage - and also, not helping at all.

What was she missing?

It was well after midnight, and her eyelids weighed a metric ton (each). Mary stared with growing hate at the spot where she knew the book to be, still seeing nothing but the wood of her desk. She tried many things, moving to more and more damaging methods, which all failed to show any effect.

She swayed in her chair, and her eyes fell on a candle that was lying on her desk for no practical reason she could think of. Her dormitory lay in the electric-lit part of the academy. Still, the candle gave her an idea for a test she hadn’t tried yet.

“At this point, I’m not sure if I’ll be more annoyed if it works, or if it doesn’t,” she muttered to Mossie, which simply ignored her. The SJW did that a lot when she wasn’t doing anything fineable.

She lit the candle with a modified version of the fireball spell - she noticed that botching the pronunciation resulted in a smaller flame, and skipping the finger caused the flame to remain in place. It was curious on the one hand and quite reliable on the other, but she still wouldn’t risk trying it on the book directly anyway.

She held the candle close to the page, and… it started to appear.

“Oh, come on.”

Heating one page took around two minutes, but to say that the effect wasn’t what Mary hoped for would be quite an understatement. First of all, she saw all the stains and destruction she inflicted on the volume while testing. Oops.

But the second problem was worse. Instead of letters, it had rows of dots punctured in the paper in various patterns. Mary wanted to scream - she recognised the patterns immediately but couldn’t read them anyway.

The book was written in Braille.