The Impossible Cube

“We’ll figure it out later,” Gavin said. “Open the cages before the Gontas recover.”

The second and third children were more eager to leave their cages, which convinced the first child. Alice had just freed the tenth and final child when a horde of gibbering, angry Gontas appeared at the entrance of the hallway leading back to the operating theater. Ivana was at the forefront. They quickly spotted Gavin, Alice, and Feng. With a shout, they ran down the stairs. They had paused long enough to arm themselves, for they bristled with weapons—energy pistols, thunder rifles, vibration knives, quantum swords. They boiled down the steps, bounding with plague-enhanced speed, and rushed toward the three escapees and the children, who cowered in fear. Their demonic howls echoed off stone walls, and spittle sprayed from their mouths. Phipps was nowhere to be seen. Perhaps the electric shock affected her more because of her metal parts. Simon and Glenda were no doubt still in handcuffs.

Alice’s lips moved, but Gavin had put the ear protectors back on and he could no longer hear her. Feng looked unfazed, but adrenaline zinged through Gavin’s arteries. The Gontas and Zalizniaks weren’t going to capture now. They intended to kill. Praying his plan would work, Gavin let the rucksack fall to the floor, revealing the paradox generator. He pointed the speaking trumpet toward the pack of screeching clockworkers and spun the crank hard.

This time, even through the ear protectors, he heard the faint sliding sound of the tritone paradox. It simultaneously climbed and dropped, spinning and swirling. The gaps between the intervals were all tritones, an auditory square root of two that itself stretched out into infinity, but each tritone was paired with a mirror of itself, a parallel. Instead of being painful, the sound became perfection. The sound twisted the universe into new shapes, teased the ear the way a star’s gravity teased a comet. Gavin heard only a tiny part of it, and he felt a singular joy.

The effect on the clockworkers was electric. They stopped dead in their tracks, dropped their weapons, fell to their knees with the backs of their hands dragging on the floor. Every one of them stared at the generator with an open mouth. Most of them drooled like half-dead demons.

“Get the children,” Gavin said, though it was difficult to speak. “We’ll have to take the lift.”

Alice mouthed something at Feng, who immediately herded the children toward the lift with Alice coming behind. Gavin stayed to keep the paradox generator going.

And then Danilo Gonta appeared at the top of the steps in his bloodstained white coat. He was wearing ear protectors. Gavin tensed.

“Shit,” he muttered. He hadn’t noticed Danilo wasn’t among the crowd of Gontas he held captive with the generator, or remembered that Danilo hadn’t returned after Ivana had sent him from the operating theater. Both of Gavin’s hands were occupied with the generator, and Alice and Feng were already halfway to the lift with the children.

Danilo bounded down the stairs and stopped just a few steps away from Gavin. He didn’t have a weapon, but that didn’t mean he was unarmed. Gavin took an uncertain step backward, still cranking the generator. The faint but perfect beauty of the tritone paradox was a constant distraction.

The clockworker reached into his pocket. Gavin tensed again, and Danilo pulled out a metal stylus with a glass bulb on the end. A wire ran from the other end of the stylus and disappeared up Danilo’s sleeve. He moved the stylus across the air, and it left a trail of light. Gavin stared in fascination, and he almost forgot to crank the generator.

We can hear this sound a little, Danilo wrote in glowing letters. It creates unity! It is perfection! Name price.

Gavin shook his head. Alice and the others were almost to the lift now.

Danilo waved the stylus and the words vanished. He started over. We will let you and children go. We will send you on special train to China. We will stop Phipps.

Where was Phipps, anyway? Gavin had a hard time believing she had been incapacitated for long.

“No,” Gavin said, his voice muffled in his own ears. “You’ll use it to control each other and other clockworkers and God only knows what else.”

Danilo’s face hardened in clockworker anger. Then we destroy you and your circus and take friends for test subjects.

Feng opened the gate to the lift and Alice herded the children aboard. She gestured at Gavin to come. He thought about an army of Cossack clockworkers and their weapons tearing through the Kalakos Circus, of Dodd and Nathan and Linda and Charlie and all the others being carted down here, infected with the clockwork plague or strapped to a table and cut open like Feng. Was that worth an invention he had intended to destroy in the first place? His hand slowed on the crank.

“You have to promise to let everyone go,” Gavin said.

Done, Danilo wrote over the heads of his drooling family.

“And to arrange for that special train.”

Danilo underlined the word done. His lips also moved as he muttered to himself, and Gavin, used to reading lips on windy airships that often swept sound away, saw him add Ivana and other words he assumed were Ukrainian. The clockwork plague helped him make lightning connections in Gavin’s mind. Realizations snapped and clicked together, and Gavin’s blood went cold. Danilo was lying. He had no intention of letting anyone go. He—they—wanted to use the generator as a weapon against the Gonta clockworkers, and Danilo Zalizniak would do or say anything to get his hands on it. The Cossacks, who had already broken a compact with Phipps, would have no compunctions about breaking one with Gavin.

He sped up the crank. “No!” he shouted. “I’ll see you in hell first.”

Danilo leaped at him with a snarl, smearing golden letters. But Gavin’s combat training with the Third Ward took over. He jumped straight up and caught Danilo in the chest with a snap kick that barely interrupted the generator’s lovely drone. Danilo fell back and slammed into Ivana, who toppled over without caring. One side of Danilo’s ear protectors came off, exposing him to the tritone paradox, and a look of ecstasy descended on his face. He sprawled across Ivana’s plump body, already drooling.

“Your second orgasm of the day,” Gavin said, and kicked him in the crotch. “That’s for Feng and the children, you son of a bitch.”

The thud as his boot connected felt good. For a moment, Danilo’s face vanished, and it was replaced by Madoc