The lawn rolled away from her, grass neatly trimmed to a uniform length and groomed around a few small shrubs. It was like someone had taken a well-maintained park and rolled it into a tube, like a cigar. It was obvious that the direction of down changed with the floor, since the shrubs halfway up the curve of the wall stood just as straight as the grass under Alice’s feet. She couldn’t help following the ground with her eyes, fighting a dizzy sense of vertigo, to where it began to curve back. Directly overhead, a small brook burbled happily through a rocky watercourse, oblivious to the fact that it ought to have been raining directly down on Alice’s head.

Alice found herself laughing as she looked about, in spite of the desperation of their circumstances. She wanted to run all the way around until she got to the brook, and look at Soranna standing upside down on the ceiling. She really wanted to see what would happen if she threw something high enough to reach the very center of the tube, halfway between the walls. Which direction would it fall?

“I think I’m going to be sick,” Soranna muttered. She glanced fearfully at the ceiling, with its upside-down stream. “Esau ought to have kept his books under better control. My master would never allow such foolishness.”

“We just have to stay long enough to find Isaac and Dex,” Alice said. “Come on.”

The doorway was easily visible, a rectangular depression in the turf covered by a mat of grassy roots. Satisfied she could find her way out again, she led Soranna across the grass, looking for a landmark.

It didn’t take long to find one. In the middle distance, there was a commotion—Alice saw a group of large creatures gathered together, like a herd of sheep. In its midst was a small building, made of neat brown bricks and roofed with wooden shingles. It looked like the groundskeeper’s shed on a better class of golf course. As they approached, Alice caught first a chorus of angry honking sounds from the creatures outside, and then, distantly, the faint strains of a melody she recognized.

“That’s the Siren,” Alice said. “Isaac uses her to put things to sleep. And if he’s using her, I think he’s in trouble.”

“Those things do not look friendly,” Soranna said.

Taking a closer look, Alice had to agree. They were about the size of horses, with fat turkey-like bodies covered in dark feathers, a pair of orange, scaly legs ending in big clawed toes, and two long, flexible necks, each ending in a bullet-shaped head with beady black eyes and a long, sharp beak. The neck and head feathers were a riot of green, blue, red, yellow, pink, and every other hue Alice could imagine.