Silver said nothing.
“Maybe it’s like you said,” Lash answered. “This is the only way Liza can be sure of a successful termination. But I think there’s more. Remember how I told you the murder profiles made no sense? Artless, identical, as if a child was committing them? I think, emotionally, Liza is a child. Despite her power, despite her knowledge, her personality hasn’t attained adulthood — at least, not in any way we’d measure it. That’s why she killed those women: a child’s jealousy, irrational and unrestrained. That’s why she did it so ingenuously, without trying to vary her methods or escape detection. And that could be why she’s destroying herself like this now, no matter what happens to us or this building. She’s simply doing what needs to be done, as directly and efficiently as possible — without considering the ramifications.”
This was greeted by silence. Silver did not look up.
“That’s all very interesting,” Sheldrake snapped. “But this speculation isn’t going to save our asses. Or the building.” He turned toward the youth. “Dorfman, what about the private floors of the penthouse? Do they have sprinklers?”
“If they’re like the rest of the tower, yes.”
“Could they be diverted?”
“Possibly. But without power, you’d—”
“Water works by gravity. Maybe we can jury-rig something. Where’s Lawson and Gilmore?”
“Down in the baffle, sir, trying to deactivate the security plates.”
“That’s a waste of time. Those plates won’t open until power’s restored and Condition Gamma’s been lifted. We need them back here.”
“Yes, sir.” And Dorfman scampered off.
Mauchly turned. “Dr. Silver? Any ideas?”
Silver shook his head. “Liza won’t respond. Without a communications channel to her, we’ve got no options.”
“Override the hardware manually,” Tara said. “Hack our way in.”
“That’s what I’ve taken every precaution to prevent. Liza’s consciousness is distributed across a hundred servers. Everything’s mirrored, each data cluster is isolated from every other. Even if you managed to trash one node, all the rest would compensate. The most sophisticated hack couldn’t bring down the system — and we don’t have time for even the crudest.”
The haze was growing a little thicker, the surrounding hardware screaming as it was taxed beyond its limits. Lash could feel sweat beading on his brow. To his left, there was an ugly grinding sound as some electromechanical device gave way with a shower of sparks and a belch of black smoke.
“You never built a back door?” Tara said over the noise. “A way to bypass the defenses?”
“Not intentionally. Of course, there were ways to simulate back-door access, early on. But Liza kept growing. The original programming wasn’t replaced, it was simply added to. I never saw a reason for a back door. In time, it became too complex to add one. Besides—” Silver hesitated. “Liza would have seen it as a lack of trust.”
“Couldn’t we destroy everything?” Sheldrake asked. “Smash it all to pieces?”
“Every piece of equipment has been hardened. It’s stronger than it looks.”
Dorfman came trotting back through the smoke, dabbing his eyes. In his wake were the security techs, Lawson and Gilmore.
“Dorfman,” Sheldrake said, “I want you to check out the backup generator. See if there’s a way, any way, to take it off line. Lawson, check the conduits from the generator to the hardware grid — most are probably buried under steel plates, but see if you can find any weakness, any place we could cut or divert power. And you, Gilmore, go up into the penthouse and check the sprinkler system. See if we can divert water from the roof reservoir down here. If there is, let me know and we’ll send a team up to help you. Now move.”
The three ran off. A silence fell over the remaining group.
Sheldrake shifted restlessly. “Well, I for one am not going to stand around, waiting to crisp up like a suckling pig. I’m going to search for alternate egress. There must be some other way out.”
Silver raised his eyes, watched Sheldrake vanish into the haze.
“There is no other way.” He spoke so quietly Lash barely heard over the machinery.
Abruptly, Tara grabbed Lash’s arm. “What was it you said just now? That emotionally, Liza’s like a child?”
“That’s what I think.”
“Well, you’re a psychologist. Say you’re dealing with a stubborn, misbehaving child.”
“What about it?”
“And say threat of punishment isn’t an option. What would be the most effective way of getting past a child’s willfulness, of reaching him or her?”
“Child psychology isn’t my field.”
Tara waved her hand impatiently. “Never mind, I’ll pay extra.”
Lash thought. “I guess I’d appeal to their most atavistic instincts, prod their earliest memories.”
“Their earliest memories,” Tara repeated.
“Of course, children have lower long-term memory retention than adults. And it isn’t until around age two, when they develop a sense of self, they can put a context to memories that would help you—”
Tara stopped him. “Atavistic instincts. You see? There’s a parallel in software. Except it’s a weakness.”
Lash looked at her. He noticed Silver did the same.
“Legacy code. It’s a phenomenon of very large programs, applications written by teams of programmers, maintained over years. In time, the oldest routines become outmoded. Slow. Compared to the newer routines that encapsulate it, that original code is a dinosaur. Sometimes it’s written in old languages like ALGOL or PL-1 nobody uses anymore. Other times the original programmers are dead, and the code is so poorly documented nobody can figure out what it really does. But because it’s the core of the program, people are afraid to tamper with it.”
“Even though it’s obsolete?” Lash asked.
“Better slow than broken.”
“What are you getting at?” said Mauchly.
Tara turned to Silver. “Can you take us to the original computer? The one you first ran Liza on?”
“It’s this way.” And without another word, Silver turned.
As they traced a path through increasingly acrid palls of smoke, Lash grew disoriented. The peripherals gave way to tall pillars of supercomputers; then to rows of refrigerator-size black boxes, covered with lights and switches of orange plastic; then to older, hulking devices of gray-painted metal. As they moved into the center of the chamber, away from the supporting electromechanicals, the sound ebbed somewhat and the smoke subsided.
They stopped at last before what looked almost like an industrial worktable. It was scratched and bruised, as if from years of rough handling. It supported a long, narrow, boxlike structure, with a black faceplate above a white control surface. Perhaps a dozen lights winked lazily on the faceplate. A row of one-inch square buttons ran along the control surface below. They were of clear plastic, with tiny lights indicating whether the buttons had been depressed. Only one was currently lit, but the entire device was so scarred Lash thought the others could just as easily be burned out. There was no screen of any kind. The far end of the table bent at a gentle angle, and an electric typewriter had been permanently mounted atop it. Surrounding this relic were others of similar shabbiness: an old keypunch machine; a card reader; a tall, cabinet-like box.
Tara stepped forward, peering at the device. “IBM 2420 central processor. With a 2711 control system.”
“This is the heart of Liza?” Lash asked in disbelief. The machine looked ludicrously antiquated.