They spent the rest of that day and the following day setting MOMO's plan into action. With help from Juli and Doctus, MOMO used the data from the Patmos base to develop a patch for the AMN operating system, a defensive program that would detect and block interference from the other network. The AMN Bureau used similar programs to keep track of registered corporate networks and to safeguard the AMN's core structure against hacking attempts, although this was the first time MOMO had had to consider both tasks at once.

"All right," said MOMO, stepping back from the terminal where she had been testing the program. "That should be everything." She walked over to the two open dive beds in the center of the room. "Doctus, have you uploaded the parameters for your AMWS?"

Doctus gave a brisk nod from the screen. "The Astraea's all ready to go." She would be joining the dive from her own location, meeting up with MOMO and Ziggy at the coordinates they had specified.

"Good. What about you, Ziggy?"

"I'm ready to go when you are." He and Juli had been reluctant to send MOMO into danger, but, as MOMO had pointed out, as a system administrator for the AMN, she was one of the few people in the Federation who had clearance to modify the AMN source code. Even Doctus had only limited access, her permissions restricted to the lower levels of the operating system. MOMO could have administered the patch by herself, but Doctus and Ziggy had volunteered to accompany her for protection.

"All right, I've set the dive coordinates and all systems are running normally," said Juli, monitoring several screens at once from another terminal. One of the peripheral screens displayed a constantly evolving map of the two networks, set to update every few seconds in real time. In the last twenty-four hours, the shadow network had spiraled in on the core of the AMN like a slowly contracting iris. Juli checked over the settings one last time and joined MOMO and Ziggy in front of the dive units. "MOMO ...." she began, but MOMO stopped her before she could continue.

"Please don't worry about us, Mommy. We'll all be looking out for each other, just like you always say."

She managed a faint smile, but the tension at its edges betrayed her concern. "Actually, I was just going to wish you luck. I know you'll do fine. Of course ... I'll be looking out for you too." She gripped MOMO's shoulder for a long moment, then let go and looked past her. "And you, Jan."

MOMO sat down in the smaller of the two dive units, and Ziggy took the larger one. While Juli ran through the start-up sequence, MOMO leaned out of her seat and looked over at him.

"I'm a little scared," she whispered, too quietly for Juli to overhear from where she stood. "Are you?"

He thought for a moment, remembering something she had said a long time ago, and he nodded. "It's okay. Try not to worry. Even if something goes wrong, I'll be here with you."

Her eyes brightened behind the visor of her headgear. She smiled and lay back against the base of the dive unit as the login sequence executed.

He blinked, and the world reassembled itself before his eyes. They stood at the base of the outer shell of the axis, a blank gray wall surrounded by a profusion of towers and neon-lit avenues sprawling away in every direction under an indistinct dark sky. The security programs guarding the axis prevented them from logging directly into or out of the area enclosed by the wall, so they had set their coordinates for a point just outside the perimeter.

MOMO gripped his arm and pointed. "Look over there!"

He did, and saw a vague, blurry shadow moving among the towers in a manner that reminded him of the Gnosis when they weren't fully materialized.

"Those things are all over the place," said MOMO, still in a whisper, as if she thought the shadows might hear her. "That must be what the shadow network looks like. I think I can use the Hilbert Effect on them if they get too close."

He nodded. "Let's hope we don't have to find out. It looks as though they haven't reached the axis yet."

The Astraea loaded into existence behind them. "Looks even worse from the ground, doesn't it?" said Doctus. "We'd better get a move on before they get here. Just remember, once we're inside the firewall, we won't be able to log out again until we get outside, so be prepared to run like hell if something goes wrong."

"Right." MOMO detached herself from Ziggy's arm and went over to the wall. She placed her hand on the smooth surface, and an intricate pattern of glowing pathways radiated from where she had touched it. A moment later, a section of the wall dissolved, leaving an opening large enough for Doctus' AMWS to pass through easily. MOMO stepped inside and waved for them to follow.

They stood at one end of a walkway leading across a chasm to a massive pillar-like structure which the outer wall surrounded like a sheath. From a distance the column looked solid, but Ziggy had seen it up close during its construction, and he remembered MOMO explaining that it was actually made of thousands of spiraling strands which were made of thousands of smaller strands in turn, and so on down to the minuscule fibers of information that formed the axis of the AMN, bundled together into an immense multi-leveled helix like the genetic blueprint for some impossibly complex life form. The chamber itself appeared about a mile in diameter, extending into darkness above and below the path.

They had gone about halfway across when the first tremors jolted through the walkway like the aftershocks of a distant explosion.

"Watch out!" cried MOMO, bracing herself as her ether bow materialized in her hands. "Something's coming!"

Ziggy assumed a defensive stance in front of MOMO, although he recognized the uselessness of trying to protect her now--it was impossible to tell which direction the attack would come from, and he couldn't guard every direction at once. "MOMO, are your sensors picking up anything?"

"I--I can't tell!" The floor shuddered, and she staggered against him to catch her balance. "The readings are extremely confusing. I'm detecting something, but I can't make any sense of it!"

"Keep going!" said Doctus, bringing the Astraea up behind them. "You have to make it to the center before they do. I'll stay here and hold them off. Just hurry--I don't know how much time I can buy us."

"Doctus, no! What are you--" Ziggy stopped himself, surprised by his own outburst. "You can't take them on alone. What's going to happen if you're overpowered?"

"Never mind! If I have to, I'll force an emergency logout and bypass the firewall. I'm using my artificial body as a proxy, so it won't affect me the way it would if I were directly linked to the network, the way you and MOMO are. If I disconnect without a proper logout sequence, it might cause some damage to my circuits, but it's nothing that can't be repaired."

The walkway heaved again. He overbalanced and almost fell over the edge, but MOMO grabbed his arm and hauled him back. Sometimes he forgot how strong she was.

"We don't have time for this," said Doctus. "Listen, if I don't make it back today, I want you to remember something for me. You think you can do that?"

"What is it?"

"Project Apocryphos. Just remember that for now, in case .... I'll explain more later, if I can." She pulled the Astraea up higher as another shock hit the walkway. "But you'd better hurry up, or you won't make it out of here either."

"Doctus, thank you so much!" MOMO called as they set off running. "We owe you!"

"Don't bother keeping track of it," she called back. "As far as the Captain here is concerned, I'm just doing a favor for an old friend."

Ziggy didn't understand what she was talking about, and it wasn't until they had made it across that he realized she had referred to him by his former title. The recognition hit him like a gunshot, and he whipped around, but the Astraea was out of range, a luminous figure floating above the abyss. For a moment he wished he still had the interlink device installed. He didn't know what he would have said to her, but he wanted her to know that he knew.

He turned back to MOMO. She stood in front of the pillar on a platform that joined the walkway. "Is there something I can do?" he said.

She looked over her shoulder. "Just stay with me while I install the patch. It shouldn't take long, but--" Another tremor struck, and he reached out to steady her, but she had already recovered her balance. She managed a nervous smile. "I feel safe when you're with me."

"I won't leave you," he said, moving closer. After a moment he noticed a shift in the light moving through the spiral strands of the column.

"That should do it." MOMO turned around. "At least, it should stop anything from hacking into the operating system for now."

"Good work, MOMO. Now we have to find a way out of here." They both looked back across the walkway. The Astraea still hovered in the distance, but now the darkness surged and wavered around it, racked by explosions and sudden flashes of light.

"They're already here," said MOMO, with no attempt to conceal her dismay. "The other network wasn't supposed to reach the axis yet. How could it have spread so fast?"

"I don't know. Doctus said the network might have some sort of consciousness. Maybe it's aware of us."

Light flared in the distance. MOMO gasped and clung to his arm again, and he moved to shield her as another shock wave reached them. When he looked back again, he saw no sign of the Astraea in the living darkness.

Which was suddenly advancing much faster than before, boiling toward them in a shimmering, shivering mass like a heat wave, and MOMO tugged his arm--she hadn't let go yet--and half-led, half-dragged him to the edge of the platform. "Come on!" Before he could object or resist or even understand what she was doing, she stepped off the edge and pulled him after her.

A second platform opened beneath them like a round raft bobbing up from the depths. A few more steps, and each time they ventured out onto darkness another raft appeared, extending the main platform in the opposite direction of the walkway. "What is this?"

"An escape route," said MOMO, and for a second he thought she was being facetious until she explained. "It's sort of an emergency exit system. It only works if you have special permission, and only administrators like me are supposed to know about it. So don't tell anyone, okay?"

"I won't." He ran alongside her and the platforms rose to meet his strides, like ripples in water. Behind them the first links in the chain had begun to fade, growing transparent and sinking back into the darkness.

The field of distortion created by the shadow network surged toward the axis, then suddenly pulled apart and flowed to either side of it, as if repelled by the change in the light. "It worked!" said MOMO, but they had no time to celebrate, because the darkness ahead of them was suddenly alive as well, and then it was all around them, a churning, writhing, seething, whispering wall of shadows.

MOMO drew her bow and stepped back into a combative stance. Ziggy retrieved his own weapon and did the same, and they stood with their backs to each other, facing the darkness. "Looks like we're surrounded again," he said.

"Don't worry." She activated the Hilbert Effect, and the insubstantial mass began to lighten and solidify at its edges, revealing a knot of thick rope-like structures that had an organic appearance. From the corner of his eye the structures seemed to take on any number of forms--bodies, outstretched hands, faces he almost recognized--until he looked in that direction and the illusions disappeared.

He launched a round from his cannon. Where it struck, a section of the wall turned ashen and crumbled away, but before he could fire again the visible part of the wall caved under and more darkness billowed in around it. "It's no use," he said. "What do we do now?"

MOMO backed against him, slipping her left hand into his right. "I don't know. I think it really is the end this time."

He nodded. This time, neither one of them had to say any more. He held onto her hand as the darkness flooded around them.

∞

The shrill pitch of warning signals filled the room. Juli leapt up from the monitoring station and ran to the dive units, her heart pounding so hard the noise in her ears almost drowned out the alarms.

The faces of the two unconscious figures hadn't changed, and all their life signs read normal. It was just their coordinates she had lost, an instant after the gathering threads of the invading network pulled to either side around the axis. She had tracked their progress since the dive began, plotting their coordinates on the same map of the network where she had been tracking the invasion. The two points corresponding to MOMO and Ziggy had disappeared a few minutes after Doctus' signal cut out, but without leaving behind a scribble of fragmented data the way Doctus had when she disconnected. They had merely vanished along with their dive records, as if the dark shape had erased them from existence.

She hurried back to the terminal and pulled up the window she had been using to communicate with the dive-support team from Scientia. "What's--" she began, but the Scientia technician finished speaking before her.

"What's going on?"

"I just lost track of their coordinates," said Juli, fighting to keep the panic out of her voice. "Can you tell where they went?"

"Negative," said the technician. "Although if they're somewhere on the shadow network, our instruments wouldn't be able to pick them up anyway."

"They're on the shadow network?"

The technician went on as if he hadn't heard Juli. "Its behavior has become increasingly erratic. There's so much interference we can hardly track its movement anymore. It's as if the structure of imaginary space itself is distorted inside it, and everything around it is getting pulled in."

She gripped the back of the chair in front of the workstation. "So what does that mean?"

The technician shook his head and shrugged.

Juli gripped the chair harder and was about to advise him to take a wild guess when she noticed an incoming call on another screen. The alarms were so loud she hadn't heard the call. She slammed a few keystrokes, cutting the alarms off mid-shriek, and picked up the transmission. "Representative Helmer? Is this important?"

"I suppose that depends on the relative importance of whatever I'm interrupting," said Helmer. "However, we've just received word of a string of attacks on Federation military installments in the outer regions, the same places where we've observed the highest incidence of post-Ormus activity. You asked me to keep you informed, so I thought you should be the first to know."

"I see." Juli pressed her lips together, afraid to say more; in her mind a voice screamed, Not today, damn it, not now. One goddamn crisis at a time! But it was the same crisis, after all. That seething inkblot on the screen connected everything, like a network of invisible roots spanning miles underground. Whatever had attacked those ships had also erased Ziggy and MOMO and had caused the deaths of civilians and Federation diplomats in Patmos, and there was no telling what else it had already done, or what it might do next.

"Additionally," said Helmer, "all of the targets broadcast a message to Federation military headquarters within minutes of their destruction. By themselves, the messages were fragmentary, but when read in order ...."

Juli shook her head. She knew what he was going to say, and she knew she wouldn't like it.

"Why don't I just send you a copy of the message and you can read it for yourself," he said apologetically.

"Go ahead." She glanced over at the other communication screen, distracted for a moment by the Scientia technician's attempts to get her attention.

"It's on its way now. Dr. Mizrahi, I hate to pry, but I noticed I seem to be interrupting something. Is everything okay?"

Juli stared at the screen without comprehension, as if Helmer had just started speaking in an unfamiliar language. "Yes, it's ... I'll explain later. For now, I'd appreciate if you would continue to keep me updated on the situation, and let me know if anything changes."

"I plan on it," said Helmer.

After he had closed the transmission, she brought up the message he had sent, ignoring the Scientia technician for a few moments longer while she read it.

"Dr. Mizrahi, are you there?"

She spun around to face the first screen. "What is it?" she said, more harshly than she had intended.

The technician flinched and backed away as if he thought she could strike at him through the screen. "It's--uh--the network is--"

Juli glanced at the display. Around the central helix of the AMN, the fibers of the shadow network had begun to unravel, peeling away in tatters. "I see. MOMO's upgrade appears to be working." She swallowed hard, feeling suddenly calm, as if she had arrived at a place beyond fear. "What's going to happen if they're trapped inside the network when it breaks down?"

"I--I don't know," said the technician, in a voice that suggested he had a fairly good idea of what might happen, but he didn't want to tell her. "I suppose, I mean, if they were incorporated into the network, it's conceivable they might, um, also break down with it."

"Then we need to get them out before that happens."

"What?" The technician blinked and lowered his arms, and an embarrassed look crossed his face, as if he'd suddenly realized he was cowering from a hologram.

"I said we need to get them out. I don't care how we do it, but it has to be done. I'm going to try to open a line of communication into the shadow network. If I can contact them, I might be able to initiate a logout sequence."

"But--"

"If you have any other ideas," she said mildly, "don't keep them to yourself."

That kept him quiet, and with another glance back at the dive beds--hang on, just hang on, she thought, and she didn't know whether she meant it for them or for herself--she sat down at the control station and went to work.