And she darts out of the library and conscientiously closes the door behind her and gallops off.
Blueberry comes back, leading a bigger, older pony with spiderweb marks on her flanks.
"I know it's probably confusing, but I promise we can get everything sorted out," she says. "You just have to give me something to work with."
"I have a special talent for communication," she says to the duck. "Which means I can tell when creatures understand me, and I can usually guess how to get them to understand me, and I can understand them if they mean to be understood. My name's Cherry Cordial. I don't want to make trouble for you, but it's important for Blueberry to know if you're a dragonlike creature or not. The spell she used has a known flaw where it can accidentally grab the wrong person if the person it's looking for is near other people of similar species. If it can accidentally grab random sparkly ducks when it's looking for a dragon, that's a whole different thing. If you really don't want to answer, I can just tell Blueberry I couldn't talk to you and get her to send you back, but it'd cause a lot of trouble that could be avoided."
Who comes back in, and flicks her tail in a shruglike fashion, and opens up her other-direction sending scroll, and sends the duck back where she came from in a large puff of glittery black smoke.
Blueberry starts trying to refine the spell some more. That flaw is turning out to be much more inconvenient than initially projected.
"Hi, Blueberry! I tried to get out of it but apparently if I'm gonna let you out of the ward, the headmaster's wife needs to check you out, that's only necessary the first time and shouldn't come up again. She just does a mind scan thing with green-group dragon magic, she won't look at anything besides whether you're dangerous. If you want to skip it I can send you home and we can just work in Equestria instead, she can't stop me from being summoned. Oh, and this is Aar Kithen, but he can't tell how old you are by looking, nobody except dragons is going to be able to do that unless they see more ponies, I kind of recommend not bringing it up."
Blueberry giggles. "Okay. Sure, I don't mind a mind scan. Although I'm curious about how it works!"
"Keo's the only person who can do it at the moment," explains Kaylo. "Occasionally a dragon hatches with extra dragon magic and can do extra color-group-relevant things. Green groups are empaths, ones with a little extra are telepaths, ones with a lot extra are pretty arbitrarily mentally powerful. Aaaand she says she's done -" He turns to Aar Kithen, says some things in Leraal, gets a nod, and smudges the chalk. "There you go, she's all done, congratulations, you're certified safe."
"Dragon magic sounds interesting. I want to learn all about it!" she says brightly, trotting out of the circle.
"You and me both!" he says, waving at Aar Kithen. He pulls a scrap of scratch paper out of his pocket, looks at it, puts it away, and casts a spell. "There's your translation, now anybody'll understand you when you talk and vice-versa." He leads her out into the hall.