"It's so weird!" agrees Duck. "They're roommates, but I don't know why he's always following Mytho around. But apparently he knows about the heart shards." She can say that, right, that's a secret Serafin already knows? 

She knocks on the closet door. "Just hang tight, Mytho, there's gotta be another key around here somewhere!"

"Or I could break the door down but that might be overkill."

"...I think maybe we'd get in trouble for that? But if we can't find a key or a librarian then we can, uh, think about it."

There does not appear to be a librarian on duty, but there is a set of keys hanging underneath the front desk. (It's not stealing if you return it right away.) She fiddles with the keys and the lock for a bit, gets the door open, and -

The closet is empty, but there's an open trap door in the floor.

"Is this going to end in some sort of magic nonsense," says Serafin, already starting for the trapdoor.

"Probably? You don't have to check it out if you don't want to," she says, because checking out all the weird magic nonsense and looking after Mytho is her job.

"If you go down the ominous trapdoor I am coming with you, because if I don't and you get hurt I'll be very upset about it."

" - oh. OK then. I'm definitely going down the ominous trapdoor."

"I figured!"

Down the ominous trapdoor they go.

Apparently there's a series of stone tunnels under the library. If they were a little stinkier they might be sewers, and if there were bodies then they would be catacombs. They're damp, cold, and beyond a few lit candles, they're very, very dark.

"Spooky," he comments.

"Yeah," she says, frowning. "Wonder where Mytho got to."

They hear what sounds like the laughter of a young girl, coming from deeper in the tunnels. "Oh, hello! Would you like to play, too?"

"Sure!" says Duck, dashing off into the tunnels in an effort to follow the voice to its source. This is incredibly creepy, but she's found that being nice to creepy people is generally better than the alternative. "What's the game?"

—why is she—okay sure. Serafin follows.

- pendant's glowing. Yep, this is the right way.

"I'm just a little thing, but I flood the entire room," says the girl, from up ahead.

Oh, so like, a riddle. Hm.

...what? That's a weird riddle.

She runs until she gets to a fork in the path - one path lit by candles, the other pitch black. Also those things in the wall look like they might be bodies, maybe these are catacombs.

"Um, so like - a dripping faucet?"

The girl laughs at her; it's coming from the unlit path. Duck motions to Serafin and then follows the laughter, her path lit only by the soft glow coming from her pendant. Also those things in the wall are definitely bodies. 

"Too bad," says the girl. "I'm a white snake that swallows the sea. What am I?"

"Very confusing?" suggests Serafin, following along and glancing around at the bodies lining the wall. Fun stuff.

"It's no fun if you don't try," says the girl. Duck leads them down another darkened hallway. "Last one. I become shorter the longer I stand."

"Ummmm. Oh! Oh! A candle!"

"That's right!" says the girl, delightedly, as Duck leads them into a larger room that doesn't seem to have any exits. "Congratulations."

This room not only lacks exits, it also seems to lack... girls. This is concerning. Serafin is concerned.

"The person you're looking for is here," says the girl - the girl's voice, anyway.

"Great!" says Duck. "We answered the riddle, can we go now?"

"No," says the girl.

The door they came in through is suddenly blocked by solid, impassable rock. Even Duck's pendant stops glowing. They're in total darkness.

—there are two reactions he could be having to this development, and for a moment he's torn between them—

But he's caused himself enough trouble by getting angry recently (his hand still hurts from punching Fakir), and Duck seems to know what she's doing and is going for the 'be nice' option—and the 'be nice' option helped him surprisingly much, although that could just have been the magical ballet princess—

He takes a tentative step into the darkness. "Hey, uh, candle girl... are you okay?"

" - oh. Oh, now this is interesting."

Nobody can hear this voice, it just really, really enjoys talking to itself.

"No," says the girl's voice, leaving them in darkness for the moment. "But I'll be better now. You're down here."

"Did nobody tell me today was Kidnapping Day?" he mutters under his breath—