Joe grabbed Mucum’s shoulder until the boy almost winced. “Mealworms! If yow see ’un, aim for the mouth and pray to yowr godly Diana that yow live to tell the tale!”

Both boys looked into Joe’s fishlike eyes to see if he was joking. He wasn’t.

One of the gang pulled out a watch piece and checked the time against the printed tide table next to the porthole.

Joe rested his hand against the slightly hairy outer surface of the Xylem. “Never forget, the Tree’s alive, boyo. And She loikes a drink, just like yow and me. She goes reg’lar as clockwork. Tide’s out now. Get it wrong and, well, Oi’ve lost a few of moi best that way. Yow were dead lucky last toime.”

Ark remembered the night before, clinging to the ladder, feeling Mucum’s quivering bulk above him, hearing the click of mussel shells amongst the whispering greenery, and behind that an ominous groaning from the depths, as if the tree itself was taking a breath before all holly let loose. Dead lucky.

Joe’s colleague gave the thumbs-up. It was time.

“Geronimooooo!” Joe shouted, and vanished into the deep.

Although Mucum was terrified, he wasn’t going to show it. “Right, Malikum. You went first last time. My go.” He pushed hard off the edge and was instantly gone.

Ark turned to Flo. “I’m not feeling too well, actually. Maybe I can stay here and …”

Flo smiled back sympathetically. “Yow be fine, little ’un! Now off yow goes!”

Without warning, Ark felt a shove in his back and he, too, plummeted, trying to keep his feet below him but having no idea in this pitch-black free fall which way was up and which was down.

18• A CUNNING WAY THROUGH

Gold was an interesting metal. Petronio realized that Maw must have its own version of the Rootshooters. But gold was gold, whoever dug it out of the dirty ground. And it was gold that had reflected back the glint in the Commander’s eye the previous night. The word more also had magical appeal.

The fog had finally lifted and sunlight beamed down on the high woodway. Mercury picked up on Petronio’s mood, galloping south along the reverberating planks and eating up the miles with sheer joy.

Petronio’s mind still dwelled on his extraordinary meeting with Flint. Had it really happened? The most powerful man in the North discussing the future of the country with a fourteen-year-old boy?