Doctor St. Martin latched onto both men and became their permanent tour guide in return for a chance to study them in detail. She very badly wanted to understand how the transit system and its psychic interface worked, and she believed that the two men’s inability to use it might hold part of the answer.
It was also discovered that any of the irises could be opened from the inside with a thought, similar to how one operated the transit tubes. From that point on, the stream of personnel on and off the giant alien ship was constant. Teams worked in rotating shifts, composed of everyone aboard the Shackleton except for a skeleton crew of three who watched from outside. That crew included Mason Shen who finally allowed himself to get some sleep, only to immediately return to the communications puzzle the next morning.
There were never fewer than five people aboard Zebra-One at any one time, including Marcus Donovan and Commander Faulkland, who each felt compelled to stay following their first incursion. They claimed to be quarantining themselves to avoid infecting the rest of the crew, but no one much believed them. In truth, each man was in his own way enamored with the strange alien vessel, and it would have taken a platoon of marines to drag them away.
Exploration began in a handful of key areas. They were all hollow cavities detected during the years of scanning, which the Gypsies deemed most likely to hold important systems. The team targeted the smallest ones first, and each cavity offered wonders stranger and more perplexing than the last. There was a great vaulted arcade with a ceiling lit in every color of the rainbow and columns curved like a ribcage. There was a dank cavern full of organic structures that looked like fruiting fungi, and a branching network on the lower decks that was best described as a swamp. One of the most mystifying was a perfectly circular room with concentric rings of clear water set in the floor. Professor Caldwell suspected the room might have had religious significance to the natives, but it was more a hunch than anything. No one else had a better idea.
There were also areas that were less mysterious. They discovered several large cell-like networks of rooms that were undoubtedly living quarters, each complete with its own sleep area and not-unfamiliar waste collector. The quarters were clustered around evenly spaced dining halls, while small recreational parks were always nearby.
Much of the forward fifth of the craft was full of rod-shaped structures connected in series, starting very large and getting progressively smaller and more numerous as they approached the bow, all focused on the huge cavity at the front of the vessel. Debates erupted over the purpose of that cavity, with many hoping it was a scientific array, but quietly suspecting it was a weapon.
Late on the second day, a few teams started to examine the secondary hull, which was two-thirds the length of Zebra-One’s main hull and attached by five thick struts. Unlike the primary, the secondary hull was streamlined and mainly hollow, devoted almost entirely to a series of interconnected chambers. Each one housed different kinds of machinery, including a legion of segmented manipulator arms attached to gargantuan support rings. All of that equipment, alien as it may have been, bore a striking resemblance to construction equipment back on Earth. Unless the expedition missed their mark, the secondary hull was a factory complex. The largest factory ever seen, in fact. The only question remaining was what it was supposed to build.
On the morning of the third day aboard Zebra-One, Marcus Donovan decided it was finally time to take a look at her heart. Back on the Copernicus Observatory, it was the discovery of a network of veins connected to that organ that convinced him and Rao that the vessel was biological. Now that he was aboard, he’d seen the sheaths that contained the thick, fibrous veins, but it was anyone’s guess what was inside the heart itself.
The structure was the size of four skyscrapers bundled together, and it lay at the center of the primary hull. Marcus was sure that it was the main power generator, and he absolutely had to know how it worked.
Faulkland volunteered to join him, which surprised no one; the two had become inseparable since they came aboard. Rao also came along, being twice as eager as the others to learn how the aliens generated power.
They ate a quick breakfast, looked over the old scans to get a fresh image of their destination in mind, then each of them pictured the heart and was flung through the endless maze of corridors. The entire journey of five kilometers took only a dozen seconds, and undoubtedly imparted them with enough momentum to splash them against a wall like water balloons. Marcus would’ve preferred not to think about that, but just couldn’t stop himself.
At the other end, the artificial gravity gently lowered him back down to one of the raised octagonal landing pads. Identical pads existed at every corridor entrance. Much like everything else on the ship, no one knew whether they were decorative or served some particular purpose.
Faulkland followed a moment later. He floated down beside Marcus, followed by Rao who was shaking with adrenaline and had his eyes closed. Considering the fact that Rao usually had to be sedated before orbital launches, merely closing his eyes was a significant step in the right direction.
Marcus had expected the heart to already be lit when he arrived, since it was ostensibly powering every other light on the ship, but no such luck. In fact, it took longer for the room to react to human presence than any other they’d explored. When the walls finally began to glow, in a cool blue rather than the warm amber of elsewhere, they found themselves in a small cul-de-sac with no obvious opening apart from the one they’d come through.
“Think she’s screwing with us?” Faulkland asked as he, like the other two, slowly scanned their surroundings.
“I dunno. I hope not,” Marcus said. The vessel hadn’t been anything but accommodating so far. He might even go so far as to call it obedient, but was careful to keep a tight lid on thoughts like that. Just in case.
Rao drew the probe from his shoulder and started to take readings. “Maybe the generator is dangerous. Radioactive. Do you think she would reroute us away from something potentially lethal?”
“That’s not a bad thought,” Marcus said, taking a few cautious steps forward. “But then where did she take us? It seems strange having a corridor lead to a dead-end like this.”
Faulkland laughed. “Wouldn’t be the first strange thing, now would it?”
“I guess not,” Marcus said. It didn’t add up, though. A dead-end wouldn’t just be strange. It would be pointless, and he had trouble believing there was a single millimeter of anything pointless aboard. “No. I think it’s an ante-chamber. She wants to make sure we’re serious.”
Marcus stepped forward and took a good look at the wall in front of him. The room looked unfinished, like someone had just given up and stopped. It was an ante-chamber. It just had to be.
He closed his eyes and imagined the wall opening, just as he’d done with countless others. Nothing. He kept at it, concentrating on all the small details, envisioning them turning to liquid and sliding away.
There was a noise like bubbling tar. Success.
Marcus opened his eyes, and before him was the strange heart of Zebra-One. “Come on,” he said.
He stepped forward onto a platform that hung over a great dark abyss, and his two companions followed a couple steps behind. A moment later, the pale blue light grew and revealed the depths of the huge structure, a cylindrical room extending five-hundred meters into the distance, criss-crossed and covered with slender catwalks whose surfaces all faced toward the center. Marcus couldn’t discern which way was supposed to be down, and he started to suspect there was more than one ‘down’ in that room. The view was dizzying.