The Doomsday Vault

Alice muttered a curse, the second one Gavin had heard from her that day. “We met briefly at a ball in the spring, before he’d contracted the clockwork plague. His full name is Patrick Barton.”

“OIL. . MAN. . FAR,” said Tree.

“You can tell how far away he is, Tree?” Gavin asked.

“YESSSS. BAD. . SSSMELL.”

“How far, then?”

“MANY. . SSSSTEPSSS. SUN. . KISSESSSSS. .”

“Sun kisses?” Alice said. “What does that mean?”

Gavin hauled on a rope and pressed a pedal. In some ways, it was similar to piloting an airship. He could feel Tree’s movements as vibrations through his own hands and feet, and the creaking of Tree’s joints reminded him of the sounds an airship made as it coasted through the air, but there was also a definite jolt each time one of Tree’s feet came down, and the overall movement had an up-and-down swing to it instead of the steadier glide of the airship. Tree’s speed and his ability to step over and around traffic let them make excellent time.

“He means we’ll catch up at sunset,” Gavin said. “When the sun kisses the horizon.”

“That’s very poetic, Tree.” Alice reached out and stroked a branch. Gavin felt a bit of envy.

“YESSSS.”

They were already leaving London proper, and the houses were thinning out, fading into farmland and wooded country estates. Herds of sheep grazing near the road in their paddocks fled at Tree’s approach, and a cool breeze cleared the clouds away to reveal a heavy sun.The air smelled cleaner, more like grass and forest. Gavin inhaled appreciatively. He hated being trapped in London, with its grime and demon smoke and stony streets, its square buildings that hemmed him in and ground him down. Clean air stripped away the demonic ashes.

Just as the sun touched the horizon, Gavin and Alice saw a stone tower rise up ahead of them. It was surrounded by a ruined stone wall, and from his vantage point in Tree’s foliage, Gavin could make out the remains of several other foundations lying around it. Rose vines grew over many of the stones and climbed all the way up the tower, and a river drew a silver ribbon along one side.

Perfect place for a clockworker to hide, Gavin mused.

Even as the thought crossed his mind, the mechanical unfolded itself from atop the tower like a metal blossom, and the glass bubble gleamed in the setting sun. The figure of Patrick Barton was barely visible inside.

“What do we do?” Alice said.

“First we try to talk to him,” Gavin replied. “He might come peacefully.”

Light flashed from one of the mechanical’s arms. A moment later, the ground near Tree’s right leg erupted in a small explosion that showered all three of them with bits of sod.

“Or he might be hostile from the outset,” Alice said. “I hope you’ve prepared for this eventuality.”

“You’re awfully calm,” Gavin observed.

“Panic never solved anything, Mr. Ennock.”

Another flash of light. Gavin hauled on the lines and swung Tree around toward the river just as another explosion hit the ground where they’d been standing.

“ROCKY,” Tree said.

“That means he doesn’t like it,” Gavin explained before Alice could ask.

“Run, little mice!” boomed Patrick Barton.

“What is he shooting at us?” Alice asked.

“Simple gunpowder bombs, I think. He’s good at timing the fuses, but not so good at launching them.”

“I’m not complaining, Mr. Ennock.”

“ROCKY.”

Gavin pulled a speaking tube down to his mouth and whistled a hard G into it. The note sang out clear and loud, meaning Tree’s amplification system was working. Tree was now a few steps from the river.

“Mr. Barton!” Gavin shouted at him. “We don’t want to hurt you. If you come with us, we’ll give you a fully equipped workshop and let you work on anything you want.”

“Can you give me a moving target to practice on?” Barton shot back. “The moon is too far away.” Another bomb whistled toward them. Gavin eyed it, then yanked a line. Tree swatted the object aside, and it exploded harmlessly above the river beside them.

“Bombs bursting in air,” he muttered.

“Well-done, Mr. Ennock!” Alice called.

“LEAFY.”

“Now let’s shut him off.” He took two tuning forks from his jacket pocket, one tuned for C and one for F- sharp. He struck them against Tree’s bark and held them up to the speaking tube. A tritone, strong and ugly, rang out across the clearing. It dragged like a fingernail across Gavin’s eardrums, and he felt a twinge of actual nausea.

Barton’s mechanical put metal hands to the sides of the glass bubble. “La la la la! I can’t hear you!”

“Damn,” Gavin muttered.

“What happened?” Alice said from her own chair.

“He built sound baffle into his bubble,” Gavin told her.

“Then how can he hear you shouting at him?”

“We’ll ask after we’ve captured him.”

Barton, meanwhile, began to sing. “ ‘Hi, diddle diddle, the cat and fiddle, the cow jumped over the moon’!” Part of the vine-covered tower wall ground aside to reveal an enormous cannon, but with glassy fixtures on it. Power whined, and sparks snapped from the gaping mouth. Gavin made a small sound, and his mouth went dry.

“He’s lost it completely.” Alice was gripping the sides of her chair with white knuckles as the cannon clacked around, aiming straight at them. Tree’s branches creaked with tension. Gavin moved Tree left, then right, but the cannon tracked the movements with terrifying precision.

“We’ll be all right,” Gavin said, hoping he wasn’t lying. Tree reached the river fewer than thirty paces from the tower and stepped into the water. “Alice! Can you pump those bellows by your feet?”

“It’s Miss Michaels, if you please, and yes, I can.” She did, and there was a deep sucking sound. Tree sighed heavily.

“THIRSTY.”

A high-pitched whine shrilled through the air as the cannon powered up. Gavin swung Tree around and smacked a switch. Water jetted from a hollow branch and struck Barton’s cannon. The lights along the barrel shattered, and the cannon trembled. Its whine became a scream, and Gavin had to fight not to clap his hands over his ears.

“Keep pumping!” he shouted to Alice.

“ ‘The little dog laughed to see such sport’!” Barton barked from the tower. Water continued to crash over the cannon. And then it exploded.

The entire top of the tower went up in a spectacular firework of light and stone. Heat washed over them and blasted Tree’s leaves. An enormous boulder splashed into the water next to them. Tree stumbled backward into the river, every branch swaying, and Gavin clung to his chair for dear life. Alice looked seasick-or perhaps treesick. After a moment, Tree recovered his roots. Gavin took a deep breath.

“Is everyone all right?” he asked.

“LEAFY.”

“I am, Mr. Ennock,” Alice called. “You were incredible!”

“We need to track down Barton,” Gavin said evenly, though he was sure he had died and gone to heaven. “I don’t think the explosion would have destroyed that mechanical of his.”

“I agree. Perhaps we should-”

A boulder slammed into Tree, knocking him backward. Gavin experienced a sharp jerk, a moment of weightlessness, and a cold shock. River water exploded in all directions as Tree went down. More water filled Gavin’s mouth and nose, and he strained against the straps that held him in his chair and the pack that held him down. Desperately, he tried to undo them all, but the buckles were stubborn. He hadn’t grabbed a good breath