As the last traces of light vanished, Kurt saw lights in the crater—red dots that swarmed over every surface. Sentinels.

Will's hands flashed over the sensor panel. "New energy signatures detected. Extremely low frequencies." He looked up. "Over a hundred thousand distinct emitters, sir."

"What configuration?" Dr. Halsey asked. "Clusters, single units, or pairs?"

Will studied the panel. "Ninety-five percent clusters, a few hundred single patterns… and a few hundred dual signatures."

"Combat pairs," Kurt whispered. "Kelly, match their speed." He keyed TEAMCOM, and said, "Make ready for a hot drop. Battle-ready conditions."

Green status lights flashed back, confirming his order.

They decelerated over the darkening city, creeping toward the dome. Kurt's instinct told him this was the right thing to do. The logical, conscious portion of his mind, however, urged him to leave. He'd trust his "gut" on this one—get them inside and under cover, before every Sentinel in the place fired on them.

"Nice and easy," he said.

Kelly's hand hovered over the throttle stripe. "You think these things are smart enough to use our own tricks against us? Lure us inside and then close the trap?"

"It's a possibility," he admitted. "But I don't think they went to all the trouble to unearth this place just to blast it to bits." He shrugged. "Just a hunch."

Kelly and Will glanced at each other.

"Understood," Kelly said. "Approaching structure. Three hundred meters."

"Back us in," Kurt said.

Their ship slowed, spun around, and eased toward one of the dome archways. Five Covenant dropships could have fit through the opening with room to spare.

Inside, the blue glow of their engines illuminated the walls. The interior surfaces were angled and carved with star charts and the Forerunner hieroglyphics.

Below, seven flat surfaces, each the size of carrier landing decks, were evenly spaced.

Kelly set them down one.

Kurt exited the dropship. Will followed him, and together they helped Dr. Halsey off.

The other Spartans took defensive positions around the ship.

Kurt's motion sensor showed everyone on deck, but there was nothing beyond the landing pad save darkness. Every noise was swallowed by the vast emptiness of the interior, and he felt as if he were drowning in shadows and silence.

He initiated a single-beam COM network, and opened external audio so Dr. Halsey could hear them, too.

"We do this fast," he told his team. "Olivia, Will, scout the perimeter of this landing pad. I want a report in ninety seconds on all routes and motion sensor hits."

Olivia and Will nodded and melted into the dark.

"Linda, Fred, Mark, Holly, get grappling rounds, scale the dome, and take up lookout positions in the arches. Set up single-beam relays and zip lines. Anything moves this way, sound the alarm."

Their status lights flashed green. Linda disappeared into the ship and returned with harpoonlike shafts and rope bags. She passed them out to the three other Spartans. They slid the rounds into their sniper rifles, aimed, and shot them through the archways overhead.

Braided monoline uncoiled, pulled by the grapple. They tested the lines, and then rapidly ascended the ropes.

"Dante, Mendez, stay with the ship. Get our gear ready and loaded into balanced packs."

Dante's status light remained unlit for a full second in protest, and then it winked green.

Mendez nodded and they boarded the ship.

"Kelly, Ash, Tom, Lucy—you're with me and Dr. Halsey. Ash, grab those cut-down nukes."

Ash moved into the dropship's cargo area and retuned hefting a backpack.

"Tom, Lucy," Kurt said, "keep Dr. Halsey covered."

His senior NCOs stepped to either side of the Doctor.

"Got a staircase, sir," Will reported. "Goes through the floor and around the landing pad's support pedestal. No motion detected."

"Roger," Kurt said. "Olivia, link up with Will. Scout it out. We'll follow."

He oriented on Will's IFF tag and set a single-beam relay antenna on the edge of the platform so he could keep in contact topside.

Kurt led his team to the stairs that helixed around the giant pedestal supporting the landing pad. Kelly and Ash were right behind him, Tom came next, then Dr. Halsey, and Lucy on rear guard.

Each stair step was spaced a quarter meter, but they fanned out from the pedestal ten meters. Kurt kept to the inner surface of the spiral, avoiding the darkness that lay beyond.

Dr. Halsey paused to examine the stone surface.

Lucy halted, too, and the faint illumination of the TAG lights on her SPI armor reflected in the banded rock. She reached out and touched her image. There was translucence to the material that, for a moment, bounced reflections within the reflections— and an infinite number of Lucys appeared mirrored.

She withdrew her hand, and they hastily continued.

After three revolutions around the support, Will's IFF tag appeared on Kurt's heads-up display.

A single-beam COM channel opened. "Chamber ahead, sir," Will reported. "With Forerunner symbols, I think."

Fred's voice broke over the COM: "We're in place. No incom-ing."

"Eyes sharp," Kurt told Fred. Then to Will he said, "Show me."

Will led them until stairs passed through a floor and stopped at an arched entrance.

Olivia crouched there, rifle out, covering the room beyond. The chamber was only four meters across. After the agoraphobia-inducing space of the city, this room looked suffocatingly small.

"Watch," Will said, and took a step inside.

Holographic Forerunner glyphs—dots, dashes, lines, and polygons—sprang from the stone floor and twisted around him.

"With your permission, Lieutenant Commander?" Dr. Halsey asked. "It's not dangerous, I assure you. I have seen similar control surfaces in the Halo mission logs."

Kurt didn't like a civilian leading, but Dr. Halsey was the expert here… as much of an expert as he had at any rate.

"Very well. Doctor," he said. "But carefully."

Dr. Halsey made her way forward. "Stand perfectly still," she told him, and entered the room.

She tapped a tiny crystalline blue square; it blinked in response.

"Still dammed difficult to read," she muttered. "There is a simple two-dimensional translation, but I now see there are higher-dimensional interpretations." She reached for her laptop.

"There's no time for details," Kurt told her.

She frowned and put away her laptop. "All meaning is in the details. Lieutenant Commander." She compressed her lips, concentrating on the symbols, and then she straightened. "This way."

She started to stride across the room, and the floor lit a brilliant blue before her, running directly into a blank wall.

Kurt set a hand on her arm, gently checking her motion. He then waved for Lucy and Tom to join him and the three Spartans slowly walked ahead.

Dr. Halsey pointed to a small slightly brighter blue dot on the wall.

Tom and Lucy took up firing positions on either side of him. Kurt reached for the dot, ready for trouble.

The wall slid apart and in the darkness beyond, a bridge of light flickered on, arcing into the distance.

Kurt told Olivia, "Stay here and relay signals topside."

She nodded.

Kurt paused at the wall, testing his weight on the semitrans-parent bridge. It held. He didn't like it, though. If the power cut out, this thing could vanish.

He moved twelve paces, with Tom and Lucy right behind him… although the distance covered by their steps didn't seem to match the much greater distance he perceived he was traveling along the curve of the bridge. He looked down: fathomless shadows. He kept his eyes straight ahead.

When they got to the end of the bridge, a door of dazzling light appeared, and the shadows slid apart.

Kurt, Tom, and Lucy passed through, not registering so much as a blip of enemy contact on their motion sensors. He found himself in a half-sphere chamber twenty meters across. In the center was a console over which metallic-hued Forerunner hieroglyphs swarmed.

Kurt turned and motioned for Dr. Halsey to come along.

She strode quickly across the bridge. Kelly, Will, and Ash hurried behind her, keen for any motion.

They entered the room, and Dr. Halsey studied the hologram.

"For lack of a better term," she said, "this is an information center." She ran her hands over the symbols on the console. "We should be able to find, ah"—she tapped a tiny flexing triangular icon—"a map."

Light exploded around Kurt. Holographic geometry flashed and zoomed to a distant perspective—and a sphere of symbols, topology lines, and shapes swelled over the console, until it touched the apex of the room.

"A map?" Kurt asked.

"Of our present location," Dr. Halsey said.

"So this building is round?" Kelly asked.

"Not precisely incorrect," Dr. Halsey replied. "We are in this building. And this building is in this city, which is technically on this so-called planet, but that view is backward. Observe."

She rotated a golden circle symbol, and holographic structures passed though Kurt as the map expanded. A dot on the surface of the sphere magnified and resolved into lines and a grid, squares, triangles, and one circle.

The view zoomed in upon that circle and it tilted 90 degrees, showing depth, and a faceted dome with seven arches.

Dr. Halsey twisted the gold circular symbol and the focus sharpened, descending through the layers of the building, showing the landing pad, and the outline of the Covenant dropship with a blazing reactor core. Mendez and Ash appeared and tiny bio signs displayed next to them.

The view plunged deeper and the room they stood in resolved and Kurt watched himself, the other Spartans, and Dr. Halsey.

"And back," she said as she spun the circle icon.

The room shrank to building to city and back to the large sphere construct.

The scale of it finally clicked in Kurt's mind. Once he understood, it took him a few seconds to again speak.

"When you said the Forerunner translation for Onyx was 'shield world,'" he whispered, "that was a literal translation, wasn't it?"

"Apparently so," Dr. Halsey agreed. "The entire planet is artificial… like the Halo rings."

Something caught her attention on the console. She tapped a blue octahedron. "Could it be… ?" she whispered.

The map shifted once more, through the surface of the world, deep into the crust, and revealed a chamber full of machinery and eight oblong pods that shimmered with energy fields. Within were human bodies, translucent, their features like specters. Next to each pulsed the trace of their heartbeats.

"That's Katana," Ash said, and took a step closer. "At least five of the people in those things. They vanished in Zone 67— before this all started."

"We've got to get them out," Kurt said. "Doctor, find me a route to that location. Kelly, Ash, get the medical kits from the ship and—"

Dr. Halsey held up one hand. "One moment. Lieutenant Commander." She touched a dot.

The map of Onyx receded to a meter across and stars winked upon the map-room walls.

A tiny Covenant destroyer appeared in orbit… then another… and another, until twenty-four ships had flashed into normal space from Slipspace.

Kelly muttered, "Out of the frying pan…"

Kurt's mind raced. They could still do this. Rescue Team Katana and get out of here. But they couldn't just leave and give the Covenant the technology on Onyx. There were the FENRIS warheads, but if he detonated them all it wouldn't even destroy a tiny fraction of this planet.

"We've got incoming," Fred's static-filled voice crackled over the COM. "Sentinels."

"How many?"

"Sir, all of them."

CHAPTER THIRTY-ONE

SEVENTH CYCLE, 193 UNITS (COVENANT BATTLE CALENDAR) \ ABOARD CRUISER, INCORRUPTIBLE; IN ORBIT ABOVE PLANET ONYX-SYSTEM: ZETA DORADUS (HUMAN DESIGNATION)

Fleet Master Voro stepped up to the command console on the bridge of the Incorruptible.

His crew snapped to attention at his presence.

All was perfect. He controlled a fleet of the finest ships on what might be the most important mission for his people… and this would be his crowning moment: contact with the Forerunner guardians of this world.

"Ship Master Qunu," he said over ship-to-ship COM, "report."

On the central holographic display, Qunu's destroyer, the Far Sight Lost, continued to accelerate from the safety of the fleet's defensive sphere formation. It plunged into a high orbit over the world the humans had called "Onyx"; this word had no meaning for their translation Oracle.

"Fleet Master," Qunu replied, "moving into the proscribed vector of supplication."

A thousand tiny craft crested over the planet's northern magnetic pole and moved toward the Far Sight Lost on attack vectors.

"Honor light your way," Voro told Quno.

Quno finished the time-old Sangheili maxim: "Our blood will forge a thousand generations."

Voro had considered initiating contact himself, but decided the honor should go to Qunu, whose knowledge of the ancient ritual responses from the Fire and Repentance Codices of the First Age was unmatched.

On Y'gar's sensor station a schematic of one of the Forerunner vessels appeared: three unconnected cylinders and a sphere.

"Power signatures detected, sir," Y'gar reported, his one good eye staring at the patterns.

"Energy shields and offensive-system waveforms present."

Voro considered this: The power outputs from these tiny ships were insufficient to penetrate their shields… but there were so many.

"Spin up the fore energy projector," Voro ordered.

Uruo hesitated a heartbeat, and then moved his hands over the controls. "Fore energy projector charging, sir."

The shimmering of power readings of the Forerunner vessels reflected Voro's gaze.