It all fit together neatly. It only remained to prove the theory. Susan gave Jake a triumphant look.
But the policeman was frowning, clearly in deep consideration. “It took a total of four strong, young adults with a stretcher to carry Nate after Lawrence removed his battery at the Nineteenth Precinct. I’m sorry, but I can’t envision that many people sneaking into the lab nor a single person moving him into place.” He shook his head. “After the men who carried him testify, I don’t think a jury will, either.”
Once again, Susan realized they could prove how easy it was to move Nate in an instant; but, if she did, it would force Jake to arrest her. She glanced at Pal who gave her a quick, almost imperceptible headshake.
Then, another thought came to Susan. Once it did, it would not be banished. “What if I proved it to you?”
Pal looked away but not before Susan saw a faint green tint arise on his features.
Even Nate looked a bit nervous, though only someone who knew him well would notice.
Jake’s brows rose. “When?”
“In about fifteen minutes,” Susan said, glancing at her Vox. Only then, she realized they had spent two hours examining and debating. If she did not act soon, she would miss Alfred Lanning. Quickly, she tapped in the main number for U.S. Robots and Mechanical Men, Inc. and waited for Amara to answer. She dared not put on the speaker function. No telling what Alfred might say.
“U.S. Robots. Amara speaking.”
“This is Susan Calvin. Could I speak with Alfred?”
“Of course. Do you need his Vox number, Dr. Calvin?”
“I’d like that. Thanks.”
“I’ll send it. In the meantime, I’ll get him.”
In a moment, Susan heard the faint beep of a number being added to her Vox, then Alfred’s deep voice. “Susan? Is everything all right?”
“Fine,” Susan assured him. “I just wondered if you could bring Nick to Goldman and Peters’ lab.”
“Nick? To the lab? What for?”
From the corner of her eye, Susan could see both Pal and Nate nod as they realized what she planned to do. “Exonerating Nate and Lawrence. I’m trying to demonstrate how the crime was committed, and we’re stuck on a robotic detail.”
“It’s better if people don’t know about Nick. He has nothing to do with the situation, and it could get dangerous for him.”
Susan winced, glancing at Jake. The policeman gave her nothing but a raised eyebrow. “Trust me,” she replied. “It’s necessary and important, and it’s not going to put Nick at risk.”
Doubt tinged Alfred’s voice, but he finally said, “All right. Be there in ten to twenty minutes.”
“Thanks.” Susan tapped off the call and looked at Jake. “I trust you’ll keep Nick’s existence a secret?”
Jake hesitated. “So long as it doesn’t become an issue. I can’t afford to lie on direct questioning. You may need Nick in the courtroom, and I need my job.”
Susan could scarcely begrudge him that. “Fair enough.” She added, “I know Lawrence was only trying to protect Nick when he said USR had no other humanoid robots, but that statement may come back to bite him. If we need him to prove a point in court, I’m bringing Nick with or without Lawrence’s consent.”
Jake looked directly into Susan’s steely eyes. “Are there others?”
“No,” Susan said definitively and without any hint of defensiveness. It was the truth, and she had no difficulty meeting Jake’s gaze. “Nick and Nate are the only humanoid positronic robots remaining.”
Pal said nonchalantly, “Assuming Nate hasn’t fallen into dangerous hands, of course. No telling what the SFH might do to him.”
Susan had no choice but to wince and nod.
Chapter 13
Ten minutes later, Jake studied Nick, walking around the robot as if inspecting a car for purchase. Finally, he stepped directly in front of Nick, staring intently into his all-too-human face.
Alfred gave Susan a questioning look, but she declined to answer him. She believed Jake suspected they had brought him Nate in the guise of another robot. She hoped Alfred had prepared Nick for questions about Nate, most specifically that he would not innocently reveal his fellow robot’s disguise. She had not had the opportunity to remind the director of research, and Alfred did not always consider the human element when he made decisions.
Finally, Jake broke the silence. “What’s your name?”
Nick responded dutifully, in a voice a half tone higher than Nate’s and with an entirely different cadence. “I am N9-C, the ninth in the NC production line. I am usually referred to as Nick.”
“So you’re a robot?” Jake stated the obvious, which did not require a response.
Nick gave him one anyway. “I am.”
Jake’s next request caught Susan off guard. “Prove it.”
Nick hesitated only a moment before peeling up a layer of skin over his shin to reveal the network of wires and plastic that lay beneath it.
“Thank you,” Jake said, and Nick seamlessly rolled the dermal layer back into its proper position. The questions Susan had anticipated came next. “Are you familiar with a robot referred to as Nate?”
“I am.”
Susan glanced at Alfred, who seemed entirely disinterested in the conversation, inspecting his own fingernails.
“Tell me about him.” Jake kept his request open-ended. Susan supposed he got more cooperation and, sometimes, more information during police questionings with this technique.
Nick seemed no more bothered than Alfred by Jake’s grilling. “Nate is the common name of N8-C. He was the eighth NC robot produced by U.S. Robots and Mechanical Men.”
“And you were the ninth.” Jake repeated the information Nick had given him.
“Yes.”
“How many NC’s are there, Nick?”
Nick hesitated, clearly uncertain how to answer properly. “There are currently two, sir. N8-C and myself. All of the others were dismantled, most before my creation.”
Alfred explained. “The components for the NC line were astronomically expensive and the technology uniquely difficult. Our original intention was to wind up with a single NC robot that combined the best features of each of its predecessors and recycled most of the materials. But along the way it’s normal to find a couple or three models that stand out and really should remain intact. In the NC line, it was N8-C and N9-C. The final result, N12-C, was destroyed, as you already know.”
Susan trusted Alfred not to reveal the purpose of N12-C, aka John Calvin. The letters NC stood for New Calvin, and Jake was one of the few people who knew it.
Jake kept his attention fixed on Nick. “Do you contain any of N8-C’s components?”
Susan knew where Jake was going and also that it was relatively safe ground.
“I contain reused bits and pieces from nearly all of my predecessors, but nothing from N8-C.”
“You contain nothing from N8-C now or in the past?” Jake pressed.
“Correct. I’m mostly composed of newer resources than N8-C, since he received the best recycled materials from the previous models. However, I have none of their positronic pathways.”
This time, Jake deliberately looked to Alfred for clarification.
The scientist complied. “When we talk about recycling components, it’s bits and pieces of hardware only.”
Jake kept his attention on Alfred and finally spoke his main concern aloud. “This isn’t a trick where you give N8-C a new face and try to pass him off to me and others as an entirely different robot, is it?”
Alfred’s features grew raw with affront. “If you don’t believe me, Detective, you need only contact the board of directors at Saint Mary’s Hospital. Nick has worked there for years, and he has looked, talked, and acted the same as he does now.”
Susan added, “And Hasbro will vo
uch for Nate. So, unless someone has been shuttling the two back and forth several times a day since their placements in preparation for this exact moment, it’s simply not possible.”
Now Jake studied Susan, though he would find no clues on her face. Not only was she stating the abject truth, but she could school her features well enough to fool an expert.
Jake finally relaxed. “Forgive my paranoia, but I can’t afford to take chances.” He made a broad gesture. “Now, Susan, make your demonstration.”
Susan set up the situation quickly. “Alfred, please take a seat in that chair, and keep it facing the table.” She indicated the murder spot. “Layton, pick up the broom and stand behind Alfred.”
Nate did as Susan instructed, though with clear reluctance. He held the broom tightly in both hands as if afraid it might slip and accidentally strike Alfred. He stood far enough behind the chair that, even if it did, it could not possibly harm Alfred in any way.
“Jake and Pal, stand wherever you need to to watch this demonstration. Nick, come with me.” Susan did not bark out an instruction for Dr. Peters.
Nick obeyed, following Susan to the storage room. Once inside, she had him turn to face Alfred before instructing, “Nick, until I say your name again, you will see and hear nothing. You will remain entirely still.”
Nick froze in place, exactly as Nate had done in Susan’s apartment. Susan walked behind him. “Can you see what you need to see, Jake?”
“I can,” he called back. “Work your magic.”
Susan planted her hands on Nick’s shoulders and gave him a strong push. He was lighter than Nate, in the two-hundred-fifty – to three-hundred-pound range, and she could easily slide him toward where Nate waited, hands clenched to the broom handle.
Susan braced for a second push, but Jake stepped up beside her. “Let me try.”
Susan gestured broadly, stepping aside to allow Jake to take her place. He had no more difficulty than she did moving Nick without the robot assisting in any way.
Jake executed a flourishing motion more suitable for royalty in the Middle Ages. “I bow to your superior intellect, Susan.”
Susan could not help grumbling, “Well, it’s about time.” She turned her attention to the robot. “Nick, back to normal.”
Instantly, Nick returned to his regular state, glancing around to reorient himself to his new position.
Peters’ Vox buzzed.
Jake addressed Nick once more. “Are you still working at Saint Mary’s?”
The robot shook his head. “I’ve been recalled.”
“To U.S. Robots?”
“Yes.”
Susan suspected Peters’ call had something to do with the radiation badge, but she dared not desert the current conversation. It could turn dangerous for her.
Jake continued calmly, as if his questions stemmed from curiosity rather than duty. “Was Nate also recalled?”
Nick replied smoothly, “Not to my knowledge.” He struck to the heart of the question. “He’s not at U.S. Robots if that’s what you’re asking me.”
Jake could not let up. “Not even in part?”
Nick tipped his head in perfect mimicry of human consideration. “I believe his old battery might be there.” He turned to Alfred Lanning. “Isn’t that right?”
Alfred nodded. “I do have the battery. Susan brought it to me directly from Lawrence, and I performed some tests on it.” He added gruffly, “Are you finished with us, Susan?”
Susan appreciated the request. The longer Jake had to throw questions at Nick, the more likely he would discover Nate’s presence in the room. “I am, Alfred. Nick. Thanks so much for coming on such short notice. I know you’re very busy.” She had taken a dangerous gamble, but it appeared to have paid off. For now, at least, they had one policeman firmly on their side.
Peters had wandered off to talk on his Vox, but he soon returned and stepped right into the middle of the discussion. “Aiden, I’m going to put you on speaker. Can you tell everyone here the findings from my dosimeter?”
Aiden’s now-familiar voice came crisply through Cody’s Vox. “Hi, Everyone Here. Dr. Peters’ dosimeter was exposed to a single pulse of electromagnetic radiation at approximately two o’clock p.m. on September first.”
Susan recalled that the first code had come over her Vox at 2:19 p.m., which fit the scenario. The killers would have needed several minutes to leave things the way they wanted the police to find them and to make the calls.
Alfred asked one of the few questions that did not spring to Susan’s mind. “What type of radiation, Aiden?” He added politely, “This is Dr. Alfred Lanning.”
“Electromagnetic, Doctor, from a nuclear source.”
Susan knew little about radiation, but Alfred clearly did not suffer from her lack. “X-rays or gamma, then.”
Aiden seemed to enjoy discussing the situation with someone knowledgeable in the field. “The difference is mostly semantic. It’s the kind of thing I’d expect to see if someone deliberately dosed himself with fluoroscopy. A single exposure of fifty-six millisieverts.”
Jake stepped closer to Alfred. “Does that match what you found in the battery?”
Susan wished Alfred would just say yes but knew he would answer like a scientist. Nothing was ever true or false, black or white, and everything was possible. “Examining a battery isn’t nearly as precise as checking something specifically created to measure radiation exposure like a dosimeter. By my calculations, using the results of battery testing alone, it was subjected to a single pulse of radiation early to midafternoon on September 1, 2037. That’s about all I could figure out.”
Pal translated, “So, yes. It gibes perfectly.”
“It gibes,” Alfred admitted, though he avoided the adverb. “But I can’t definitively prove it was the same exposure. We may need to bring the two together to see how perfect it is.”
Aiden spoke up. “Doc, why don’t you send the battery to me? I could compare them.”
Susan studied Alfred. U.S. Robots and Mechanical Men had good facilities, but they could not possibly compare to a mega-hospital laboratory.
“I’ll do that,” Alfred promised.
“Deliver it to the Radiation Lab, lower level of Mayner Pavilion,” Aiden said. “I have to admit, I’m curious. What’s this battery from? Someone’s Vox?”
Cody Peters returned to the conversation. “Actually, it’s the battery from a robot. And I’m wondering just how dangerous fifty-six millisieverts is.”
Aiden sounded rehearsed, and he probably was when it came to discussions of radiation exposure. “The average American exposure from natural background radiation over a year’s time is just under four millisieverts. Currently, our chest X-rays dose patients five to six millisieverts. A whole-body CT scan could expose a patient to as many as thirty millisieverts.”
Peters interrupted. “So my coat, the robot, and, possibly, Ari took in about two full-body CTs’ worth of gamma radiation.”
“Right. One hundred millisieverts is considered the lowest annual dose at which the risk of developing cancer becomes evident. It’s also what we consider the five-year limit of exposure for our radiation workers.” Aiden added, “The important thing is whether you were wearing that coat at the time of the exposure.”
“I wasn’t,” Peters assured Aiden. “I wasn’t even in the building.”
“Good,” Aiden sent back sincerely. “Of course, Dr. Goldman’s exposure is moot. Whether or not a pulse of fifty-six millisieverts would affect a robot, I have no idea.”
Alfred had an answer. “A positronic brain is far more susceptible to all types of radiation than a human one, but we’ve never had a reason to do an in-depth study of how various types and dosages affect it. Positrons are antielectrons. Anytime we want to destroy a positronic brain, we need only use a simple electron source. As far as radiation, beta is p
articularly dangerous to the positronic brain because it consists of ejected electrons, but it doesn’t have enough power to penetrate more than a few millimeters of metal. A sheet of aluminum foil can stop it. Gamma radiation?” He shrugged. “Let’s just say we don’t sell . . .” He amended quickly, based on his earlier conversation with Susan. “Pardon me. We don’t lease positronic robots as radiation technicians. Most of our research comes from the Mercury robots.”
Aiden indicated he had followed the explanation. “So fifty-six millisieverts might be enough to seriously damage a robotic brain?”
“I don’t think so,” Albert said. “The LD50 in humans is what?”
Aiden had the figure. “It’s five thousand millisieverts, Doctor.”
Jake looked askance at Susan, so she explained the word she suspected was giving him trouble. “LD50 is the lethal dose for about fifty percent of the exposed population given current medical treatment standards.”
Jake grimaced, and it occurred to Susan that it was a rather gruesome, but effective, way to measure the dangerousness of a toxin, drug, or pathogen.
Albert did not seem to notice the exchange. “Robots don’t have LD50 because they all react pretty much the same way. For them, it’s a short step from LD0 to LD100. Any differences in robot survivability would depend solely on the human-built shielding or construction. With something as fully penetrating as gamma radiation, and based only on previous experience, I’d say the LD100 for exposure in robots is probably in the two-hundred-millisieverts range.”
Aiden summed up Alfred’s point. “So fifty-six wouldn’t hurt it?”
Isaac Asimov's I, Robot: To Preserve Page 25