Spartacus followed up its stab at the shuttle with a full-scale assault aimed at getting into the Hub, both by pushing northward out of the Spindle and by breaking in from the outside. It brought its full complement of new weapons to bear, including cannon-firing and flame-throwing spacedrones and self-propelled bombs, but the defending troops were prepared for depressurization and faced the assault wearing suits and well entrenched behind formidable walls of rocket launchers and automatic weapons. The battle developed into an ebb and flow concentrated mainly around the region where the Hub joined the Spindle and around the vicinity of Northport.
Somebody in the Hub had the idea of loading some of the cabs with explosives and dispatching them down the tubes through the Spindle into Detroit, in hopes of an explosion somewhere deep inside Spartacus's vitals. Some of the cabs never made it and nobody was sure exactly where the others were when they detonated, but not long afterward the vigor of Spartacus's attack slackened considerably. A counterthrust developed from this point with spacesuited infantry regaining a number of positions in the Hub-Spindle junction; at the same time a swarm of bugs that had been specially rigged to fire rockets and Gremlins went out to deal with the machines attempting to work inward from the outside. In some places troops emerged onto the outside surface to add further pressure.
The tide turned once more when Spartacus's 'Mark I' missiles proved lethal for bugs and its space drones took out the infantry, who had no equivalent weapon of their own to counter them and were soon forced back inside. When a lull at last developed, the soldiers were still holding the exits from the Spindle but Spartacus had gained sole ownership of the outside.
By this time most of the Hub was a mess. Its surface was pitted with jagged holes and most of its outer sections were depressurized. Several of the Hub backup stations had been knocked out during the fighting, leaving many units to maintain their vigils by the ghostly glare of portable searchlights, without transportation and in some cases with only hastily laid field telephones for communication. Evacuation under those conditions would have been impossible and all personnel who were not directly involved in the military operations being conducted at the Hub began moving down to the Rim.
Throughout all this, Dyer had been totally preoccupied with digesting the reports coming in and endeavoring to form a picture of what kind of processes were developing inside Spartacus from the tactics that it employed. When things calmed down again he returned his attention to his immediate surroundings and looked around for Laura, Chris and Ron. There was no sign of them. He descended from the dais and went across to where Jassic was still sitting.
"They went after Kim," Jassic told him. "I tried to talk to them but things were too hectic. They figured you'd be tied up for too long up there and said there wasn't time to wait."
"Don't they know there's a war on at the Hub?" Dyer stormed.
"They said you'd understand. Chris said they were heading for the Maintenance & Spares Unit in Section 17D. They seemed sure that's where Kim would be."
"Get me a connection to somebody there," Dyer said.
"I already tried to. Comms there are out. The backup station got bombed."
Dyer swore in exasperation and drove a fist into his palm. He turned around to look back at the dais and saw Linsay and Krantz still debating hotly. Linsay was in favor of launching another thrust into the Spindle to follow up on the blow dealt by the cab bombs while the advantage lasted; Krantz wanted to disperse the lower shield and plan for an evacuation through the Rim. Dyer swore again. Even if he told them about Kim and the Spin Decoupler now, they'd do nothing but talk until it was too late. There wasn't time. He swung back toward Jassic, who was watching him expectantly.
"If anybody wants me I've gone to the Hub," Dyer said. "There's nothing left to do down here anyhow. It's all soldiers' work now."
He left the Command Room, stopped in the lobby outside to put on his helmet and combat overjacket and pick up an M25, and walked through from the Data Executive Sector into the concourse to catch an elevator for the Hub.
Minutes after Dyer left the Command Room, news of fresh activity on the outside of Detroit came through from the two remaining ISA ships. For some time Spartacus had been enlarging one of the holes it had cut in a position south of Detroit's equator and thus invisible from the Hub and the observation points at the intersections of the spokes with the Rim. Something was coming out.
Roughly cylindrical, over twenty-five feet long and thin for much of its length, the construction was adorned with a profusion of disks and flat cylinders mounted around and perpendicular to its main axis, with tangles of cables and what appeared to be dense electrical windings at places in between. Seemingly haphazard jumbles of unidentifiable equipment clung around both ends in heaps with the back end, assuming that that was the part that came out last, considerably more heavily loaded than the front. It lifted away from Detroit and began sailing outward on a course that would bring it around the Rim. Three more followed in rapid succession and spread out to space themselves equally about the main axis of Janus.
Then the two hippos detached themselves from Southport, reversed, and began swinging outward to traverse the length of the Spindle.
Krantz was well beyond curiosity by now and called for an immediate missile strike by the two remaining ISA ships. Six missiles were fired within seconds. Four went out of control and careered off into space, and the other two exploded prematurely, far short of effective range from their targets. The salvo of twelve missiles that followed claimed one of the mysterious devices, with seven attacks going off course and four detonating early. Krantz promptly called for another strike.
Command Stalley, senior officer aboard the remaining "Watchdog" ships, looked gravely back at him from one of the screens.
"We've only got fifteen missiles left. We didn't come here expecting to have to fight a full-scale war. On top of that we're a ship short because one's gone to take care of the shuttle."
"What's going wrong with the ones you're firing?" Krantz demanded.
"We don't know yet. We're still analyzing the data from the tracking instruments."
"When is Miller due to arrive with Z Squadron?" Krantz asked, referring to the five fast ISA ships that had been dispatched from Earth as soon as the situation on Janus began getting out of hand.
"Three and a half hours. Until then we're down to fifteen. You want us to risk all of them now?" A short pause ensued while Krantz wrestled with the question. The two hippos from Southport were now abreast of Pittsburgh and still moving outward from the axis. Then Stalley spoke again.
"Tracker analysis report's just come in. Every one of the missiles exhibited high X-ray emission immediately before it went haywire. Those things that Spartacus has launched must be something like flying linear bevatrons—high-power electron guns. It's using our missiles as targets for an enormous X-ray tube and knocking them out with their own emitted radiation!"
At that moment a third hippo came out of Southport and formed up with two mare electron guns and a swarm of space drones into a second fleet that began moving in the same direction as the first, which was now opposite Detroit and almost out as far as the inner reflector ring.
"We may not have three and a half hours," Krantz shouted at the screen. "Fire everything you've got now."
"Okay. As soon as we've reloaded and armed."
"How long?" Krantz implored.
"A minute maybe, but those hippos are slow."
Krantz nodded resignedly and turned away from the screen to find Linsay stooping to unlock the door in the plinth supporting his own console. When Linsay stood up he was buckling a pair of Patton-style pearl-handled revolvers around his waist; then he stooped again and took out a brilliantly polished white helmet that bore his general's insignia. There was a strange light in his eyes.
"What are you doing?" Krantz asked.
"Can't you see what's happening?" Linsay replied. "It's about to mount an all-out attack on Northport. If it gets in, we lose the Hub. If we lose the Hub, our only chance of getting back in to Detroit will be gone. Detroit must be attacked while we still have a chance. This time it mustn't fail. I intend going there and leading it personally."
"We still hold the Rim," Krantz pointed out. "Even without the Hub there would—"
"For how long?" Linsay asked. "Is that how you want it to end . . . with us cooped up in the Rim like rabbits chased down a hole by a ferret? If we get pushed back to the Rim there will be no way out."
"We can disperse the shield," Krantz said.
"Not anymore. Can't you see . . . it's only a matter of time now before Spartacus turns those beams onto the outer skin! The shield would absorb the X-rays but without the shield we'd all be fried like germs—sterilized, like bacteria! We can't disperse the shield now. Our only way out is to Detroit. That way we might win or we might die. Here we can only die."
Linsay stepped down from the dais and walked over to his staff officers to detail his second-in-command to take over and to select a handful of aides to go with him to the Hub. They departed a few minutes later.
Up on the dais Krantz found that his mouth was dry and his hands were trembling. He looked at the notepad in front of him and realized that he had been scrawling on the paper unconsciously. Scattered across the top sheet were copies of the same symbol repeated over and over again. It was the symbol of the final letter of the Greek alphabet—Omega.