"Maybe we need to challenge the premise," Karen said. "How do we know John Doe was on the shuttle?"
"We found his DNA there," Linus replied promptly.
"Can we assume it wasn't planted there?"
"I think that's safe to assume. It would be ungodly difficult to create those scratches and plant Doe's DNA in them without leaving your own DNA behind as well, and the computer only found Doe's DNA."
"And how do we know Doe's DNA doesn't match the DNA of anyone who was on the shuttle the day Miao overshot?"
"I checked Doe's DNA against the DNA of everyone who was on board. It didn't match."
"Let's be specific," Karen admonished.
"You
didn't check the DNA yourself."
"What are you talking about?" Linus said, surprised. "Of course I did."
"No.
You
didn't do it."
"Yes, I did. I fed the DNA into the computer myself."
"So you didn't check it yourself," Karen maintained with a mischievous glint in her brown eyes.
Linus began to feel like he was trapped in an Abbott and Costello sketch. "Yes, I did."
"Did you compare every strand of DNA yourself? Hold up a chart of John Doe's DNA and compare it to a chart of everyone else's DNA?"
"Obviously not. That would take decades. I fed it into ..." He trailed off.
"Yes, love?" Karen asked, and he knew she'd had the answer from the beginning.
"I fed it into the computer," Linus said slowly. "And the computer told me nothing matched."
"The computer told you," Karen echoed.
Linus disconnected the shuttle's computer bank, snatched it up with one hand, and grabbed Karen's wrist with the other. "Come on!" he said, towing her toward the door.
"Where are we going?" she demanded, putting up no real resistance.
"To see Hector."
They found Hector Valdez in his immaculate office, his waxed mustache quivering with anticipation at the look on Linus's face. As always, a cluster of grad students hovered around the computer terminal in the corner, playing god with computer code.
"Well?" Hector said. "You still owe me crepes from your first visit, Linus. And what in the world happened to your face? And yours, Doctor?"
"We had an accident," Karen said, "that wasn't really an accident."
"I need you to check this computer bank for tampering," Linus told him. "First see if you can trace an order to open an emergency airlock."
The grad students were giving Linus and Karen sidelong glances and their voices dropped. Linus made a note of their presence, then ignored them. Hector, meanwhile, connected the shuttle computer to the terminal on his desk and set to work. The holographic display that hovered over the keyboard flickered and flashed like a dancing genie.
"Crude," Hector muttered. "Very crude. Look at this. The order appears to have come from this Adrienne Miao woman, but it couldn't have—the datastream didn't originate from the terminal Miao appears to have used."
"Where did it come from?" Karen asked.
Hector typed quickly. "It came from off-site. Someone accessed the shuttle's computer remotely, ordered the computer to open the airlock, then used a small virus to mask the origin of the order. It was crudely done, and I suspect whoever did it had to work fast."
"Can you trace the real origin of the order?"
"Let me try." Hector's fingers flew over the board and he muttered technical commands to the terminal. Data flashed by, most of it meaningless to Linus. He stood by while Hector worked, trying not to show his impatience. At last Hector dropped his hands with a sigh.
"I'm afraid I can't trace it," he said reluctantly "The order to open the airlock came quickly, but the person clearly took his time scrubbing away any line leading back to him—or her. I'm sorry I can't tell you more."
"Actually, you've told us quite a lot," Linus said. "You've told us the killer is a computer expert."
Hector brightened. "This is true. The average person would have no idea how to go about this. Did you have something else you wanted me to check?"
"I want you to see if anyone has tampered with the bio-metric data of the passengers or crew," Linus said. "Especially the passengers."
"Ah! A challenge." Hector cracked his knuckles. "Let me see."
He set to work. Linus and Karen leaned silently against the wall and waited. The room became warm and stuffy as grad students cycled in and out of the office, always clustering around the terminal in the corner. Linus wondered what the attraction of that particular terminal was, but didn't want to distract Hector or call attention to himself by asking one of the students directly.
"This one!" Hector almost shouted, making Linus jump. "Here. This one. Look at this. All the biometric data files, including DNA files, were uploaded and created on the shuttle on this date here." He pointed at the display. "But this one—this passenger's data file was changed several hours later and resaved. Whoever did it forgot to change the time stamp."
Linus looked down at the display, and everything clicked. A rush of exhilaration thrilled through him, making his skin tingle and filling him with an urge to leap up and punch the ceiling.
"So that's our victim?" Karen asked, leaning in to look.
"No," Linus said. "It's our killer."
"The killer?" Hector echoed.
"Explain," Karen said.
Linus muttered to his obie for a moment, then began to pace, too restless to stand still. "While the shuttle was flying from Tether Station to Luna, the killer got the victim alone, hit him hard enough to stun him, and shoved him into an airlock. Hell, the killer may have thought John Doe was already dead. Then the killer fastened a space helmet over the sensor node and got to work on the shuttle's computer. He replaced the victim's biometric data with his own, then altered Miao's flight plan to make her overshoot the mark. When she corrected, he cycled the airlock, though the victim woke up at the last moment and tried to escape. The shuttle changed direction, but the victim's body wasn't held down, so it kept going in the original direction. Once the airlock was clear, the killer reset it, removed the helmet, and erased the incident from the computer. He was even able to change the record of keystrokes to make it look like Miao had entered the wrong flight data."
"That seems terribly complicated." Hector stroked his mustache. "Why didn't the killer murder his victim back on Earth and dispose of the body there?"
"Because DNA databases back on Earth are almost impossible to hack," Linus said. "Security is extremely tight.
But the killer had access to the shuttle's computers and could easily replace the victim's DNA records with his own, and that's what the killer wanted in the first place."
"He wanted to take his victim's place?" Karen said.
"Exactly. Once the killer arrived on Luna, he assumed his victim's identity. He gave his assumed name and a DNA sample to immigration. They checked both against the records
on the shuttle,
and of course, everything matched. He was granted entry to Luna City under his new name, and everything was both hunky and dory. Except for one little thing."
"One little thing," Karen said. "I assume the great detective has already figured out the one little thing?"
"He has," Linus replied. "The victim, you see, was coming to Luna City University to study, and all students have to take a secondary job. That job is assigned long before the student arrives, and it's already logged into various Luna City computers. The killer wouldn't necessarily be any good at the victim's secondary job, but there would be no way for him to change it without blowing his cover."
At that moment, the door opened and Wesley Yard came into the office. Everyone turned to look at him.
"There's some kind of problem with my schedule for the new semester?" Yard said. "I got an urgent message telling me to come down here about it."
"Well, Mr. Yard, technically speaking, I suppose that's true." Linus moved smoothly between Yard and the door. "There's definitely a problem with your schedule next semester. You won't be finishing it."
Yard looked wary and worried. "I don't understand."
"You work tech for the Dai Memorial Theater, is that right?" Linus asked. "How's that working out for you?"
"It's okay," Yard said. "What's that got to do with my schedule?"
"It's okay, love?" Karen came around from behind Hector's desk. "There were some pretty horrendous problems
with the lighting at Noah Skyler's show last night. And you were listed as the lighting technician. A little barmy, that. Your record says you have several years experience working theater and lighting back on—"
Yard lunged. Linus had been ready for him to break for the door, and was caught off-guard when Yard went for Karen instead. In less than a second, he was standing behind her, one hand around her throat, lifting her nearly off the ground. Karen made a small choking sound. Her bruised, purple face made it look like she was choking to death. The cluster of grad students gaped.
"I'll break her neck," Yard snarled. "So help me."
Linus broke into a cold sweat. Calling Yard down to the office had been an impulse—and a mistake. He should have sent a pair of deputies down to Yard's apartment to arrest him quick and quiet. Instead he had turned the entire affair into a circus and put Karen's life in danger. Fear for her squeezed his stomach into a tight ball.
"No one wants anyone to get hurt," Linus said, voicing a calm he didn't feel. "Why don't you just let her go and we'll talk, okay?"
"Fuck off," Yard barked. "Move away from the door, or I break her. You know I killed the real Wesley Yard. One more kill won't matter."
Linus edged slowly away from the door. "It's okay, son. I'm not going to—"
"I'm not your son," Yard shouted. "Now open the—"
And then Karen moved. Yard doubled up. Air whooshed out of him like a spent balloon and he dropped slowly to the ground. Karen kicked him on the way down. Twice.
"Idiot," she spat. "What kind of fool takes a doctor hostage? I know all the tender bits."
"You have sharp elbows," Linus said weakly.
"Damned nice of him to bring himself within range of them," Karen said. She ran her hands over her neck. "Did he bruise me?"
Considering the black-and-blue condition of her skin, Linus wasn't sure if she had meant that as a joke or not, so he didn't respond. Instead he savored the relief he felt and suppressed the urge to sweep Karen into his arms for a kiss. Then he slid plastic handcuffs on the gasping man lying on the floor and put in a call to the station.
lf Wesley Yard's real name is Donato Giacci," Linus said. "Once I got that much out of him, the rest was easy to piece together. Took a little research, though."
"So Yard—Giacci—is keeping his mouth shut?" Karen asked. She was sitting opposite Linus in his cool office, her face still bruised. The holographic stream continued to rush over stone and ice.
"He isn't saying a word. They only confess to everything in the vid-feeds." Linus ran a hand through his hair. It was barely an hour after the arrest, but he felt like he'd been working all day. "Giacci's application to study at Luna City University as a grad student is on file. Can you guess what field he wanted?"
"If it's not computers, I'll buy you lunch every day for a month."
"Safe bet," Linus said. "Giacci didn't make it in, but his undergrad roommate did. Can you guess the roommate's name?"
"Same bet, and it was Wesley Yard."
"The doctor wins again. Giacci's a little . . . off, though. I talked to a couple of his professors at Cambridge, where he did his undergrad work. They said Giacci was obsessed with studying at Luna U. Talked about almost nothing else. He even got a job working for International Flyways right after he graduated in order to be closer to Luna. Giacci is a great programmer, and he was fairly quickly assigned to work the Luna shuttle. It must have been some kind of torture for him, seeing the place just out of reach, and it must have pushed him over the edge when he was turned down but his old roommate got in."