"And the cause?" Halberstam asked.

"We can't be sure," she answered. "It may not be as simple as a mere overproduction of dopamine. There may also be hypersensitivity of the brain's dopamine receptors."

"It has to be some sort of IC-induced biofeedback," Park said.

"Impossible," McAllister countered briskly. "Our intrusion counter-countermeasures are state of the art. There's no way IC could get through."

Park scratched his crew cut and swiveled his chair so that he was facing a bank of a dozen trideo monitors that were linked into the facility's computer system. Most of their holographic projections showed ever-shifting views of the Matrix-colorful but commonplace images of datalines, geometrical system constructs, and beautiful but surreal sculpted landscapes.

Three of the trid monitors, however, were frozen on a single image-or series of images. Park stared at one of them. The three-dimensional image the monitor was projecting jerked and bounced as if it were a closed-circuit feed from a vidcam held by someone who was running. Filling the display was the image of a woman who the viewer seemed to be chasing. She strode purposefully away from the viewer, shoulders squared and head turned away, her face hidden by long, dark hair.

For just a moment, the scene shifted. The woman was suddenly facing the viewer as the vidcam operator jogged around in front of her, taking up the too-low perspective of a person on their knees, or of a child looking up at an adult. The woman's face, revealed, was horrifying. It was twisted in a terrifying snarl-that of a ravenous vampire with blood-flecked fangs. She licked her lips with a bloody tongue, then leered down at the viewer, mouth gaping wide…

Then the perspective suddenly shifted back to the original image-that of someone following a woman who was walking steadily away. The jogging motion resumed as the chase began anew.

The trideo monitor was labeled: SUBJECT 3. Park thumbed a button on the side of the unit and activated the aural component of the display. A child's voice echoed from the speakers. "Mom?" it said hesitantly. "Is that you? Please don't leave me. I want to go with you. Mom?"

"The same general sequence keeps repeating," Park said. "Kid chases woman, kid catches up, woman scares kid. Although the woman's face is different each time. The combinations are always human and animal, but they're freaky. Nightmarish. They have a surrealistic flow.

"It's like the kid's on a drug trip or something," he added. Then he laughed and cocked an eyebrow. "Maybe someone slipped some coke into the tanks when we weren't looking."

McAllister gave Park a withering look. She shook her head disdainfully at the joke that she seemed to take as a serious attempt by Park to explain what was going on. "If any drug was introduced, it's more likely to have been L-dopa. But with our security, I doubt it. Unless we have a practical joker in our midst."

Park's pale blue eyes stared into space as he continued following his original train of thought. "Or maybe the kid's just having a nightmare…"

"Thank you, Doctor Tong, for your in-depth analysis." McAllister snorted.

Halberstam watched the exchange without comment. When he spoke, it was with the voice of authority. "Whatever is causing this is coming from outside the clinic," he said. "From the Matrix. It's localized in the Seattle grid. It's not interfering with any of the functions of the Matrix, or with any of the hardware that supports the Seattle RTG. If it was, we'd have been hearing panicked news reports coming out of Seattle by now. Whatever this glitch is, it seems to be affecting only the users of the system themselves. As a precautionary measure, we've warned the other subjects to stay away from that RTG until this is cleared up."

He glanced once, briefly, over his shoulder at the trideo monitor. "Number Three appears to be experiencing a loop in its programming, one that was induced by something it encountered in the Seattle grid. But the imagery does not conform to any of the universal matrix specifications codings. That suggests that, if it is IC, it's highly sculpted."

"The IC may be corrupting the reality filter of the subject's MPCP," McAllister suggested.

Park's eyes rolled at McAllister's sudden acceptance of the fact that IC could, after all, have penetrated their defenses. Just because Halberstam said it was so didn't make it so. "Kiss-hoop slitch…" he mouthed behind her back.

"The key point seems to be that dopamine's involved," Halberstam continued. "One of our candidates at the Redmond clinic is experiencing what sounds like a psychotic episode. She's suffering from extreme agitation combined with hallucinations."

"What?" Park asked, coming out of his reverie. "Is she schizophrenic?"

Halberstam stared for a moment at Park. Then he smiled. The biotechnician might be sloppy, he might be a daydreamer, but sometimes he could come up with answers. He'd just earned his nuyen.

"Right," Halberstam said, his voice terse with excitement as he made his decision. "We'll try to correct the problem by introducing an anti-schizophrenic drug to the nutrient. We'll start with chlorpromazine on Number Three, and observe the results."

McAllister favored Halberstam with a kiss-hoop smile. "Brilliant!" she said with a brisk nod, ignoring Park's contribution. "Block the dopamine receptors with a binding agent. That should stabilize the subjects."

Park stared at the flatscreen projection of the brain. "At least we won't have to worry about the kid suffering any side effects," he added with a laugh. "Body rigidity, tremors… Kid doesn't know how lucky he is to be noth ing more than a ghost in the machine." He frowned. "Or how lucky she is."

Halberstam left the room at a run, heading for the part of the facility that contained the holding tanks.

09:52:32 PST

Dark Father heard Bloody guts cry out and turned to see what the fool had gotten himself into this time. A second ago, the troll decker had been a distant speck, almost to the top of the wall of skulls. Now he was plummeting down toward Red Wraith…

No, not Red Wraith. Toward another decker, one he'd never seen before. A dark-skinned woman in a tight, gauzy wrap and elaborate headdress and-Dark Father strained to see details-what looked like frayed evening gloves on her hands.

Dark Father grimaced as he realized that the troll was about to crash into the other decker. He held his breath and half turned away, not really wanting to watch but held in horrified fascination just the same.

Then the world shifted beneath his feet. Suddenly sideways was down. Dark Father fell onto the wall of skulls, which a second ago had been a vertical surface. He struggled to free himself from the tangle of fiber-optic cables and then rose to his feet on the bumpy floor. The rounded skulls were slippery under his feet, like wet cobblestones.

He looked up and saw Bloodyguts tumbling along the floor in a tight somersault. The troll rolled end over end twice more and finally came to a stop within touching distance of the new arrival.

His curiosity piqued, Dark Father made his way back to where a rather shaken Bloodyguts was climbing to his feet. It was slow going-Dark Father had to brace a hand against the mirror that now formed a wall beside him and pick his way carefully through the tangle of fiber-optic cables that littered the floor. He saw that Red Wraith was heading back from the opposite direction. Because he walked above the floor-rather than on it-he reached the others long before Dark Father did.

By the time Dark Father arrived, the three were already deep in conversation.

"… so this is the Seattle Visitor Center database?" Bloodyguts was asking.

The female decker nodded and said something about accessing an LTG address. Now that he was closer, Dark Father could make out the details of her persona. She'd chosen to appear as a black woman-although her skin had a grayish tinge, just as his own skin did in the real world. It looked as though patches of mold were growing on it. Her arms were wrapped in mummy bandages and her jackal-headed headdress was gilded and inset with sparkling gems. Like the rest of them, her persona icon was that of a dead creature. Dark Father wondered if she too had once died and then been reborn…