He retracted the eyepiece from the cabinet, and rotated the wheel to extend the scope out of the stairwell tower. The periscopes were placed so he could look right down at the mill entrances. When he peered through the eyepiece, he saw the intruders carried enough light with them to verify his worst fears.

“Professor?” Cade had followed him. “Are they Inspectors?”

The professor nodded. “A fair mob of them.” He shook his head. “How could this happen? Everything I’ve done, everything I’ve worked for . . .”

“We have to get out of here,” Cade said.

“The underground—”

“No,” Cade said sharply. “If they know about the mill, they’ll be at your house, too. The underground may be compromised, and we’d be trapped.”

“Yes, yes, of course. You are right.” The professor swept a shaking hand through his hair. He thanked goodness for Cade’s calm thinking, for all he could think of was his world coming to complete and utter ruin, that Silk and the empire had won. He had lost everything. Secrets were such fragile things. He led the way back into the artifact room, striding toward the aisle where they’d left Karigan.

“Professor, we need a way out,” Cade said, his voice louder.

As if to augment his urgency, the pounding now echoed up the stairwells at both ends of the room. The Inspectors were attacking both entrances. Long ago, the professor had reinforced the doors from inside with steel, but they would not hold up forever under a determined battering from Inspectors.

“Yes,” the professor said, approaching the spot where Karigan lay. “All else may be lost, but you will have to protect Arhys.”

“I will, but we need a way out. And we’re not leaving without Karigan.”

“Of course not.” Maybe, the professor thought, here was his chance to redeem himself, to regain Cade’s respect. “There is a way out, my boy. If there was one lesson I learned years ago from the fire that destroyed the rest of this complex, it was to always ensure there was an extra route of escape. Collect my niece . . .” He sighed. “Collect the young lady and follow me. Don’t forget her bonewood—she may have need of it when she wakes up.”

Cade did so, strapping Karigan’s satchel across his shoulder and gathering the bonewood staff. He made lifting Karigan on his shoulder look effortless. The Old Button was strong, very strong.

They hastened to the stairwell and the professor grabbed a taper. They clattered down the stairs as fast as they could go, though Cade followed more carefully with his burdens. The professor paused, holding the light so Cade could see better, and what the professor saw in turn was determination and concentration on Cade’s face. His student would need both not only to escape the mill, but also to evade capture once he was on the outside. Poor Karigan hung limply, draped over Cade’s shoulder as though dead. The professor was sorry, so sorry for what he had done to her. Cade had awakened him to his terrible error in judgment, but now he would make it up to them both.

When Cade caught up, the professor continued down the spiraling stairs, the battering on the doors growing louder and louder. He kept going past the second floor, and the first, heading down into the low-vaulted brick basement. There the banging on the doors grew muffled.

“I thought we weren’t going underground,” Cade said.

“Not to that underground,” the professor replied.

He led Cade past the one trap door that led to their secret passage, and hurried by the flyball governor that had once controlled the volume of water flowing into the mill’s turbines. They passed by the first two penstocks and stopped at the third—a huge metal pipe bent like an inverted elbow, fabricated in riveted sections. The penstock had once funneled water from the canal to beneath the floor and into the turbine. The force and pressure of the water carried in by the penstocks forced the turbines to spin-spin-spin, which set the complex network of gears, drive shafts, and pulleys into motion, in turn powering the machines. But alas, this mill had not seen the power of water in many a year. Not since the fire.

Cade looked at him questioningly.

“After the fire,” the professor explained, “the penstocks were closed off. The canal authorities did not wish to waste water power on a defunct mill.” He pulled a section of the penstock away like a hatch, metal screeching. “Therefore, not only is the penstock dry, but the tailrace tunnel as well. Mostly anyway. Fortunately there have been no floods this spring. The tunnel will take you to the river, where I’ve hidden a small boat. It may be hard and a little cramped with the young lady slung over your shoulder, but you will manage.”

“Aren’t you coming?” Cade asked.

“I’ll follow you shortly. I have some matters to take care of first. You get Karigan out. Take care of her. When she wakes, tell her how sorry I am, and that I hope she finds her way home.”

A furrowed line formed between Cade’s eyebrows. “You sound like you aren’t coming.”

“I’ll do my best, Old Button, but we’re running out of time.”

Inside the rusty walls of the penstock was a step ladder instead of the turbine shaft that should have been in there. Cade dropped Karigan’s satchel and the staff down and they thudded to the bottom. Cade then stepped through the opening into the penstock, balancing himself on the ladder, only his head and shoulders clearing the hatch. Meanwhile, the professor held Karigan. She was rather like an oversized ragdoll, but he was relieved to note she was still breathing normally, if slowly. Briefly her eyes fluttered open—he caught a glint of them in his light, but all too soon they closed again.