Mucum was more than worried as he tried to avoid Flo’s moony eyes. “Yeah. Righto.” He wished Joe would get a move on.

“Yow looks wonderful!” mimicked Ark with a whisper.

Mucum tried to dig his elbow into Ark’s arm, but the smaller boy easily darted out of his reach, an impish smile on his face.

Before they ascended the ladder, Joe grabbed two long rubber tubes, connecting them to holes at the back of the boys’ suits. Ark’s gaze followed the line of the tubes to the other side of the Xylem, where a machine resembling a crude bellows was manned by two huge insectlike creatures walking around a well-trodden circle. In the dim glow of the liquid gas, they reminded him of something he’d seen before, but in a very different place and on a much smaller scale. He couldn’t believe it! Surely they weren’t giant water boatmen, like those that skittered across the cruck pools high in the canopy?

Once Joe was connected, he pointed at his mouth, making circular motions. Air supply. He climbed the ladder, and the boys followed. At the top, there was a small opening in the tube. Joe leaned through it and peered down into the Xylem before easing himself through and disappearing from sight.

Ark felt a tug on his air supply pipe, and Flo motioned that he should follow Joe. As he squeezed through the opening onto a small ledge inside the cool, slippery Xylem tube, a damp smell of rain and sky rose up through the darkness that dropped away sheer below. Ark gulped. There was no safety ladder, no gaslights to help them on their journey. The thought of all that empty space made his head spin.

Once Mucum had joined them, Joe attached a brass shield to the opening. The world closed off around them, except for a small hole for their air supply pipes.

“Yow might need these.” Joe handed them two long pieces of thin, multicolored tubing with a trigger at the end. “Two between us should be plenty!”

“Amazing!” said Ark, admiring the way these strange objects shimmered like miniature rainbows.

“They be forged from fire opals, dug from the deep!”

Mucum peered in the hole at the top of one of the tubes.

“Do yow really want your head blown away?” shouted Joe, pushing the end of the tube away. “It’s a gas harpoon!”

“Keep yer hair on!” said Mucum, before remembering that was probably not the best way to address a bald Rootshooter. “Wot’s it for?”

Joe pointed over the edge of the hole and down into the blackness. “Worms!”

Mucum laughed. “Oh yeah. Sure!” There were sunny afternoons he’d skived off at the scaffields, watching farmers digging the soil. Those little wrigglers that turned up under the spade were hardly of the killer variety.