or trojans are found, they never make it to the mainframe.”
Lee nodded. “ But how would it be in anyone's particular interest to sabotage that?”
Parsons snorted. “Because all the extremists on this rock have their own worries about the administrator receiving a message they don't get to hear first. If there's no secure scanner, then coded orders can't be sent here, because there's no other means of decryption. So if the Earth Union Steering Committee gets taken over by Neo Luddite extremists and orders that Callisto is to be shut down, the Earth Union would have to send it in the clear, which gives the Outbounders a fair amount of warning.”
“And the Sols?”
Iseult shrugged. “They fear the opposite: that the most moderate Greens in the Earth Union Steering Committee might begin reversing the current crackdowns and even order the reacceleration of the Outbounder hull construction programs. The Sols would see that as undermining the urgency of their own radical anti-Earth agenda, so, given advance warning, they might successfully undermine that trend with key acts of terrorism.”
“Okay, so there's reason to suspect both sides of sabotaging the scanner. I'm assuming you already investigated and came up empty-handed?”
Perlenmann nodded.
“Okay, so do you at least know how today's explosion was rigged, what kind of bomb was used?”
Jack Carroll, the blister-faced engineer, pulled a small plastic sleeve out of his breast pocket, pointed at the blackened mass inside the bag. “There was no bomb involved. The saboteur used that electric igniter, slaved to a common wrist-watch.”
Iseult leaned forward. “Que? How can one have an explosion without an explosive?”
“When there's still some hydrogen in a fuel tank, you don't need an explosive, Doctor. Just a spark.” Carroll frowned, thinking. “My guess is that the saboteur's first move was to rig the fuel tank's level indicator so that it would read ‘empty' a little prematurely. That would keep the pumps from completely purging the tank after a processing run, which means that some of the liquid hydrogen would remain at the bottom of the tank.
“But, when the level indicator registers the tank as empty, the cryogenics shut off. So the tank begins to heat up a little—enough to cause the liquid hydrogen to evaporate into its very flammable gaseous form. At that point, all you need is one little spark and wham—you get one hell of an explosion.”
Lee frowned. “Who on Callisto would have the knowledge and technical expertise to set this up?”
Carroll's face did not betray what his voice suggested; that only a rank newbie would ask such a question. “Everyone, Lieutenant—with the possible exception of Dr. Iseult and some of her staff. And all the various models of igniters are easy to acquire, since we use them for so many tasks: for burning off waste gases, as starters for auxiliary power plants. They're ubiquitous.”
Lee sighed. No easy answers there.
Parsons rose noisily. “If we're just about done, I've got some people in the infirmary that I'd like to visit.”
Perlenmann hadn't even completed his nod of acquiescence before the fuel ops chief was out the door. Iseult and Carroll were close behind. Lee rose to follow.
“Lieutenant, a moment—if you please.” Lee regained his seat slowly. Perlenmann smiled. “I trust you've had warmer welcomes, Lieutenant. Although I confess surprise that you are out here at all.”
“Just luck, Mr. Perlenmann. It was my turn in the patrol rota—”
“You misunderstand me, Lieutenant. I mean I find it unusual that you are in the Customs Patrol.”
“Oh. That. Well, unless you were bluffing earlier, you've already seen my dossier.”
Perlenmann smiled faintly. “I have. Which is precisely why I'm asking what you're doing out here. A history major, with a minor in literature? And with dissident parents? I'm surprised you were even allowed to go to college.”
Lee smiled, knew it was crooked. “Administrator, that's not the kind of—er, ‘politically incorrect candor' I am accustomed to hearing from a Green official.”
Perlenmann shrugged. “I don't recall saying that I am a Green. Or anything else, for that matter. However, you will find in the course of your investigation, Lieutenant, that there is a great penchant for affixing labels around here. I suspect you arn't particularly susceptible to that kind of blind partisanship, but allow me to emphasize what you probably already know. It will not help investigator to assume that labels are either useful or accurate.”
“Probably no better than it does a facility administrator—even one so unusually articulate one as you, Mr. Perlenmann. So tell me, what are you doing in this plush job?”
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