It was Emma, frantic, out in the hall. “What are you doing?” she said again. She couldn’t see the hollow. Didn’t know it was there.

I took my hand away from its head, slid back from it. “I don’t know,” I said. “I think I was sleepwalking.”

“It doesn’t matter,” she said. “Come quick—Miss Peregrine’s about to change!”

* * *

Crowded into the little room were all the children and all the freaks from the sideshow, pale and nervous, pressed against the walls and crouched on the floor in a wide berth around the two ymbrynes, like gamblers in a backroom cockfight. Emma and I slipped in among them and huddled in a corner, eyes glued to the unfolding spectacle. The room was a mess: the rocking chair where Miss Wren had sat all night with Miss Peregrine was toppled on its side, the table of vials and beakers pushed roughly against the wall. Althea stood on top of it clutching a net on a pole, ready to wield it.

In the middle of the floor were Miss Wren and Miss Peregrine. Miss Wren was on her knees, and she had Miss Peregrine pinned to the floorboards, her hands in thick falconing gloves, sweating and chanting in Old Peculiar, while Miss Peregrine squawked and flailed with her talons. But no matter how hard Miss Peregrine thrashed, Miss Wren wouldn’t let go.

At some point in the night, Miss Wren’s gentle massage had turned into something resembling an interspecies pro-wrestling match crossed with an exorcism. The bird half of Miss Peregrine had so thoroughly dominated her nature that it was refusing to be driven away without a fight. Both ymbrynes had sustained minor injuries: Miss Peregrine’s feathers were everywhere, and Miss Wren had a long, bloody scratch running down one side of her face. It was a disturbing sight, and many of the children looked on with openmouthed shock. Wild-eyed and savage, the bird Miss Wren was grinding into the floor was one we hardly recognized. It seemed incredible that a fully restored Miss Peregrine of old might result from this violent display, but Althea kept smiling at us and giving us encouraging nods as if to say, Almost there, just a little more floor-grinding!

For such a frail old lady, Miss Wren was giving Miss Peregrine a pretty good clobbering. But then the bird jabbed at Miss Wren with her beak and Miss Wren’s grasp slipped, and with a big flap of her wings Miss Peregrine nearly escaped from her hands. The children reacted with shouts and gasps. But Miss Wren was quick, and she leapt up and managed to catch Miss Peregrine by her hind leg and thump her down against the floorboards again, which made the children gasp even louder. We weren’t used to seeing our ymbryne treated like this, and Bronwyn actually had to stop Hugh from rushing into the fight to protect her.

Both ymbrynes seemed profoundly exhausted now, but Miss Peregrine more so; I could see her strength failing. Her human nature seemed to be winning out over her bird nature.

“Come on, Miss Wren!” Bronwyn cried.

“You can do it, Miss Wren!” called Horace. “Bring her back to us!”

“Please!” said Althea. “We require absolute silence.”

After a long time, Miss Peregrine quit struggling and lay on the ground with her wings splayed, gasping for air, feathered chest heaving. Miss Wren took her hands off the bird and sat back on her haunches.

“It’s about to happen,” she said, “and when it does, I don’t want any of you to rush over here grabbing at her. Your ymbryne will likely be very confused, and I want the first face she sees and voice she hears to be mine. I’ll need to explain to her what’s happened.” And then she clasped her hands to her chest and murmured, “Come back to us, Alma. Come on, sister. Come back to us.”

Althea stepped down from the table and picked up a sheet, which she unfolded and held up in front of Miss Peregrine to shield her from view. When ymbrynes turned from birds into humans, they were naked; this would give her some privacy.

We waited in breathless suspense while a succession of strange noises came from behind the sheet: an expulsion of air, a sound like someone clapping their hands once, sharply—and then Miss Wren jumped up and took a shaky step backward.

She looked frightened—her mouth was open, and so was Althea’s. And then Miss Wren said, “No, this can’t be,” and Althea stumbled, faint, letting the sheet drop. And there on the floor we saw a human form, but not a woman’s.

He was naked, curled into a ball, his back to us. He began to stir, and uncurl, and finally to stand.

“Is that Miss Peregrine?” said Olive. “She came out funny.”

Clearly, it was not. The person before us bore no resemblance whatsoever to Miss Peregrine. He was a stunted little man with knobby knees and a balding head and a nose like a used pencil eraser, and he was stark naked and slimed head to toe with sticky, translucent gel. While Miss Wren gaped at him and grasped for something to steady herself against, in shock and anger the others all began to shout, “Who are you? Who are you? What have you done with Miss Peregrine!”

Slowly, slowly, the man raised his hands to his face and rubbed his eyes. Then, for the first time, he opened them.

The pupils were blank and white.

I heard someone scream.

Then, very calmly, the man said, “My name is Caul. And you are all my prisoners now.”

* * *

“Prisoners!” said the folding man with a laugh. “What he mean, we are prisoners?”

Emma shouted at Miss Wren. “Where’s Miss Peregrine? Who’s this man, and what have you done with Miss Peregrine?”

Miss Wren seemed to have lost the ability to speak.

As our confusion turned to shock and anger, we barraged the little man with questions. He endured them with a slightly bored expression, standing at the center of the room with his hands folded demurely over his privates.

“If you’d actually permit me to speak, I’ll explain everything,” he said.

“Where is Miss Peregrine?!” Emma shouted again, trembling with rage.

“Don’t worry,” Caul said, “she’s safely in our custody. We kidnapped her days ago, on your island.”

“Then the bird we rescued from the submarine,” I said, “that was …”

“That was me,” Caul said.

“Impossible!” said Miss Wren, finally finding her voice.

“Wights can’t turn into birds!”

“That is true, as a general rule. But Alma is my sister, you see, and though I wasn’t fortunate enough to inherit any of her talents for manipulating time, I do share her most useless trait—the ability to turn into a vicious little bird of prey. I did a rather excellent job impersonating her, don’t you think?” And he took a little bow. “Now, may I trouble you for some pants? You have me at a disadvantage.”