“It is all about observation,” Esther-Cano said to them. “Using the human senses available to you.”

Quemada was silent beside Dorotea. His handsome, even kindly features concealed his efficient cruelty — his own form of a lie. None of the Grand Inquisitor’s subjects would ever consider him a gentle person, no matter his appearance. When the twelve subjects finished their tales, Dorotea turned to him. “And what is your assessment?” She met his seemingly unthreatening gaze.

“I think your students need considerably more practice.”

“That is why they are called students.”

He gave a thin smile. “My methods are superior. The Suk School has seen to that.”

“Your methods are different, and forthright. I don’t deny their effectiveness, but ours are less obtrusive. And we do not kill subjects before they reveal everything they know. I was able to detect Blanton Davido’s deception the moment he presented himself to Emperor Salvador.”

Quemada remained skeptical. “Anyone can make accusations. I obtained a confession.”

“After I identified the crime.” She stared at him for a long moment. “There are different ways of arriving at the truth — where one method may fail, another might succeed. You and I are not in competition. We both serve the Imperium. As the Emperor succeeds, so do we.” She regarded the twelve subjects, thought of all the deception and lies that came into the Imperial court with each session. “In fact, Quemada, I may well increase your workload by acting as a screener, and sending more people your way.”

The Grand Inquisitor gave a small nod. “Emperor Salvador will be pleased to know that the lies will be exposed, by whatever method.”

Gilbertus closed the door of his office, withdrew an ornate old-fashioned key from his pocket, and turned it in the lock. He heard the satisfying click, but that was only superficial security. No one else at the school knew about his more sophisticated systems.

Even though the Headmaster asked not to be disturbed, he still applied a static seal around the door, threw additional hidden dead bolts, opaqued the window looking out on the marsh lake, and then activated white-noise reflectors, listening scramblers, and signal blockers against any sophisticated eavesdropping tools.

It was absurd to think that Manford Torondo, having condemned any technology more advanced than a medieval tool, would use surreptitious surveillance technology, but the Butlerian leader was a man of contradictions, situational ethics, and conditional morality. Although he railed against Josef Venport’s vast shipping empire, Manford traveled about the Imperium in advanced spacefolders, justifying space travel as a necessary evil in order for him to spread his important message. His followers had used advanced weaponry to destroy Venport’s gigantic shipyards at Thonaris, and he had forced Gilbertus to assist him in that operation. Manford was intelligent enough to see the contradictions in his own positions, but was so rabidly dedicated that he didn’t care.

Right now, Gilbertus did not want to take any chances. Only when he was convinced his office was secure — with physical barricades, as well as technological tricks he had learned while being raised among the thinking machines — did he feel safe.

Exhaling a long sigh, he worked secret controls on a cabinet, slid aside a false panel, deactivated another security system. Then he removed the most dangerous mind in the known universe — the memory core of the independent robot Erasmus, enslaver and torturer of millions of human beings.

Gilbertus’s mentor and friend.

The gelcircuitry sphere glowed a faint blue from its inner power source and simmering thoughts. “I’ve been waiting for you, my son.” Erasmus’s voice sounded small and tinny through the speakers. “I am bored.”

“You have the whole school to explore through your spy-eyes, Father. I know you observe every student and every conversation.”

“But I prefer my conversations with you.”

Long ago on Corrin, Erasmus had kept human slaves as experimental subjects, testing, prodding, torturing, and observing millions of them — and Gilbertus Albans had thought nothing of it. In those days Gilbertus had been a special case, a feral and uneducated young man, barely able to speak. Omnius, the computer evermind, had challenged Erasmus to prove the potential of humanity, and through tedious and unflagging indoctrination, the curious robot succeeded in converting that nameless wild boy into an exquisite human specimen.

That had changed Gilbertus forever, made him what he was today — and he knew it had changed Erasmus, too.

During the Battle of Corrin, Omnius had placed Gilbertus among other human hostages in booby-trapped orbiting containers. If the Army of the Jihad had opened fire on the machine stronghold, many thousands of innocent hostages would have been killed. Unable to tolerate the risk to his precious ward, Erasmus had left the thinking machines vulnerable so that he could save one small life — a completely irrational decision. A compassionate decision? Even Gilbertus only partially understood the reasons for the robot’s action, but he felt an intense devotion toward his beloved mentor.

Gilbertus had in turn rescued Erasmus. While the machine planet was overrun by the Army of the Jihad, he had smuggled out the robot’s memory core, which contained all that Erasmus was. Desperate, calling upon all the human skills he had, Gilbertus and a handful of other machine sympathizers escaped by mingling with the other refugees.…

Now, more than eight decades later, Gilbertus had built an entirely different life, created a new construct for himself, and never confessed his past.

“When will you let me begin experimenting on Anna Corrino?” Erasmus pressed. “She intrigues me.”

“Haven’t you done enough experiments on humans? You used to brag about it — hundreds of thousands of subjects.”

“But I have never seen a candidate as interesting as that young woman. Her mind is like an unsolvable puzzle, and I must solve it.”

“You once said I was your most fascinating subject,” Gilbertus teased. “Have you lost interest in me?”

The robot paused, as if to consider. “Are you jealous of my fascination with her? Tell me more about your emotions.”

“Not jealous — just protective. Anna Corrino must remain safe under my care. Any harm to her will bring down Imperial wrath on the Mentat School — and I’m quite familiar with your experiments, Father. A huge percentage of your subjects did not survive.” He walked to a decorative table next to his reading chair, bent over, and set up the pieces for their usual game of pyramid chess.

“I promise to be careful,” the robot insisted.

“No. I can’t risk the Emperor’s sister. I already walk a fine line with the Butlerians when I teach students your techniques without appearing to be a machine sympathizer.”

The robot was in a more talkative mood than usual. “Yes, I recognize the growing shadow of suspicion. Your crude attempts to make yourself look older are beginning to strain belief, and the years are adding up. You knew the time would come to leave this school. You need a new identity, a new life. We should leave Lampadas — it is too dangerous here.”

“I know.…” Feeling sad, Gilbertus looked at the gelsphere, which seemed so small and fragile on its stand, so impotent in comparison with the magnificent robot that once ruled Corrin, strutting about in bright plush robes.