PROLOGUE

UNSC COLONY WORLD TRIBUTE, EPSILON ERIDANUS SYSTEM, JUNE 16, 2524 (MILITARY CALENDAR)

The marines were in the air before dawn. Two four-man squads clipped to a pair of Hornet fast-attack aircraft: compact, high-wing planes that remained nimble despite the marines' combined bulk. For close to an hour the Hornets had matched the manic undulations of a volcanic plain and now—as they jerked back and forth to avoid the petrified trunks of a forest burned long ago—Staff Sergeant Avery Johnson had to work to keep his boots planted on his Hornet's starboard landing skid.

Like the other marines, Avery wore charcoal fatigues and matte-black impact plating that bulwarked everything vital from his neck to his knees. His helmet encased his recently shaved head, and its silver-mirrored visor completely obscured his square jaw and brown eyes. The only place Avery's black skin showed was at his wrists where his leather gloves didn't quite touch his shirtsleeves.

But even with the gloves, Avery's fingers were cramped with cold. Squeezing his hands into fists to keep his blood flowing, he checked the mission clock in his visor's heads-up display (HUD). Just as the luminous blue numbers hit 00:57:16, the planes crested a line of crumbling hills, and Avery and the other marines got their first line-of-sight view of their objective: one of Tribute's struggling industrial settlements; and, somewhere inside the town, a suspected Insurrectionist bomb-shop.

Even before the Hornets' pilots triggered green "ready" icons in the marines' HUDs, Avery and his team were already in motion; slapping magazines into their weapons, yanking charging handles, and toggling safety switches—a well-rehearsed symphony of preparatory clicks and snaps that went unheard in the rushing wind as the Hornets hurtled down the backslope of the hills and came to abrupt, nose-up stops on the edge of town. The thrusters on the Hornets' wingtips rotated to keep the aircraft steady as the marines unclipped from their hard-points, leapt onto the frost-covered pumice and began to run.

Avery was the leader of the strike team's alpha squad, and he took point. Seeing how his own armor stood out in the pale, pre-dawn light, he knew speed was essential if both squads were going to reach the workshop undetected. So he set a brisk pace, hurdled a low, chain-link fence, and wove quickly through piles of plastic crates and pallets that littered the parking lot of what appeared to be nothing more than a rundown vehicle repair shop.

By the time Avery and his squad reached the shop's front door, they were winded. If it weren't for the marines' helmets, their breath would have billowed bone-white in the frigid air.

They didn't usually wear heavy blast gear for rapid, airborne strikes. But the Insurrectionists had started booby-trapping their bomb shops, and this time, the marines' commanding officer (CO) didn't want them taking any chances.

Avery brought his chin down on a pressure-pad inside his helmet, sending a short burst of static across the squads' encrypted radio COM channel: an "in position" signal for Staff Sergeant Byrne, the leader of bravo squad, now positioned by the workshop's back entrance.

Avery waited for Byrne's two-burst response, then he pushed away from the workshop's pitted polycrete wall, raised a knee to his chest, and smashed his boot against the thin metal door, just above the lock.

The Office of Naval Intelligence (ONI) had suggested there would be stiff resistance. But it turned out most of the Insurrectionists inside the workshop were unarmed. Those that were carried snub-nosed automatic pistols; inconsequential weapons whose rounds simply clattered off Avery's armor as he and his squad sidled through the shattered door like hulking crabs, weapons up and scanning.

What the marines knew that ONI didn't was the real threat would come from the Insurrectionists who weren't firing—the ones with free hands who might trigger hidden explosives and blow the workshop to smithereens. The one Insurrectionist who dared took a three-round burst from Avery's silenced submachine gun and flopped back onto a steel worktable, arms outstretched and twitching. Avery watched a small, cylindrical detonator slip slowly from the man's lolling fist … and hit the floor with a harmless ping.

Major threat neutralized, the marines refocused and let the pistol-wielding "Innies" have it.

That's what Avery had learned to call the Insurrectionists—a slur that was only funny when you considered just how much the Innies wanted out—to be free of the United Nations Space Command (UNSC), the agency responsible for security on Tribute and all of humanity's colony-worlds. Of course the marines had other, shorter and cruder names for the rebels this current campaign—codenamed TREBUCHET—was designed to crush. But they all served the same purpose: it was easier to kill another human being when you didn't think of them as human. An Innie was an enemy, Avery thought. A thing you killed before it killed you.

The young Staff Sergeant had said these words so many times he'd almost started to believe them.

Avery's M7 submachine gun was a light firearm. But its five-millimeter, full-metal-jacket rounds ripped ugly holes in his targets' powder blue clean-suits. Some of the Innies Avery targeted dropped like stones. Others seemed to dance to the bullets' dull percussion, spinning bloody pirouettes onto the workshop's oil-stained floor.

Start to finish, the firefight lasted less than ten seconds. A dozen Insurrectionists lay dead; the marines hadn't suffered any casualties.

"Hell." Staff Sergeant Byrne's big Irish brogue filled the COM. "We didn't even change magazines."

To the perspiring officers in the cramped tactical operations center (TOC) aboard the UNSC corvette Bum Rush in high orbit above Tribute, it did seem like a perfect takedown—a rare victory in what had so far been a frustrating cat-and-mouse conflict. But then Avery cautioned, "ARGUS online. Haven't seen anything yet."

The Staff Sergeant pulled his chin off the COM-switch inside his helmet and continued sweeping the air around him with a palm-sized wedge of black plastic perforated by microscopic holes. This was a tactical version of an ARGUS device: a portable laser spectrometer used to sniff out traces of explosive chemical compounds. Larger, more powerful units were deployed at Tribute's spaceports, highway toll-plazas, and maglev train stations—all the major choke points of the colony's transportation grid.

Despite the density of coverage, the Innie bomb-makers had become quite adept at fooling the system by concealing their explosives in ever-changing mixtures of nonvolatile compounds.

Every time they hit a target with something an ARGUS thought was no more dangerous than, say, a bar of soap, ONI would analyze the explosive residue and add the new chemical signature to the detection database. Unfortunately, this was a reactive strategy that heavily favored the Insurrectionists, who were constantly changing their recipes.

Avery frowned at his ARGUS. The thing was clicking loudly, trying to get a lock on what it believed might be a new mix. But the firefight had filled the air with an invisible soup of chemical possibilities. The three other marines in alpha-squad were conducting a visual search, checking the workshop's clusters of autosynthesizers and machine tools. But so far they hadn't found anything that looked—as best as they could tell—like a bomb.

Avery took a deep breath then relayed the bad news to the TOC. "ARGUS is blind. Please advise, over." The Staff Sergeant had been fighting the Insurrection long enough to know what would happen next—the things they would have to do to get the actionable intelligence his officers required. But he also knew these were the kinds of things a smart marine didn't do without a direct order.

"ONI believes the ordinance is in play," replied Avery's CO, a battalion Lieutenant Colonel named Aboim. "Take the gloves off, Johnson. My authorization."

While Avery's squad searched the workshop, Byrne's quickly brought the four Innies who had survived the firefight to their knees in the center of the shop floor. All had their clean-suits' hoods removed and their wrists bound together behind their backs with black plastic ties. Avery met Byrne's mirror-visored gaze and nodded his head. Without a moment's hesitation, Byrne raised one of his thick-soled boots and brought it down on one of the nearest Innie's outstretched calves.

The man waited a full second before crying out, as if he were, like Avery, surprised that the thud of Byrne's boot hitting the floor was louder than the near-simultaneous snap of his leg.

Then the Innie screamed, loud and long. Byrne waited patiently for him to take a breath. Then, through his helmet's exterior speaker he asked, "The bombs. Where are they?"

Avery guessed one broken leg would be enough. But the Innie was tough—uneager to rat to agents of a government he despised. He didn't beg for mercy or toss out any of the usual anti- imperial invectives. He just sat there, glowering into Byrne's visor, as the Staff Sergeant broke his other leg. Without his feet to balance him, the man toppled face-first onto the floor. Avery heard the sound of teeth snapping—like sticks of chalk against a blackboard.

"Next, it's your arms," Byrne said matter-of-factly. He knelt beside the man, palmed his head, and wrenched it sideways. "Then I get creative."

"Tires. In the tires." The words bubbled from the Innie's mouth.

The marines in Avery's squad immediately moved to the stacks of large tires placed around the workshop's walls, lifted them gently to the floor, and began probing their wheel wells. But Avery knew the Innies were smarter than that. Taking Byrne's victim at his word, he guessed the tires were the bombs—that the Innies had mixed the explosives into their synthetic rubber treads—a devious innovation his ARGUS soon confirmed and uploaded to the TOC.

The tires' explosive compound wasn't in the detection database. But the ONI officer advising the mission couldn't have been more pleased. For once, they were a step ahead of the enemy, and it took less than a minute before they got a positive ID. One of dozens of aerial ARGUS drones patrolling the main highway into Tribute's capital city Casbah caught a whiff of the compound in skid marks created by a sixteen-wheel hauler as it veered into the parking lot of a Jim Dandy roadside diner. Some, if not all, of its tires were bombs waiting to be blown.

As the drone—a tiny disk, a meter wide, kept aloft by a single, shrouded rotor—circled high above the hauler, it detected a second trace of the explosive inside the Jim Dandy.

Scrutinizing a live feed of the drone's thermal camera overlaid with ARGUS data, the officers in the TOC determined the trace originated from the restaurant's crowded food counter—from a man sitting three stools from the front door.

"Marines, get back to your birds," ordered Lt. Colonel Aboim. "You've got a new target."

"What about the prisoners?" Byrne asked. The blood from the Innie's fractured legs and ruined mouth had pooled darkly around his boots.

The next person to speak was the operation's ONI representative—an officer Avery had never met in person. Like most ONI spooks, he preferred to remain as anonymous as possible.

"Is the one who talked still alive?" the officer asked.

"Affirmative," Avery replied.

"Pack him up, Staff Sergeant. Neutralize the rest."

There was no sympathy in the officer's voice—not for the kneeling Innies nor their marine executioners. Avery clenched his jaw as Byrne switched his M7 to semi-automatic and shot each Innie twice in the chest. The three men fell backwards and did not move. But Byrne gave them each a dead check—another single bullet to their foreheads—to be sure.

Avery couldn't help staring at the carnage, but he did his best not to let the torn blue fabric of the Innies' clean-suits and the white smoke curling from Byrne's weapon imprint in his mind's eye. Memories had a habit of coming back, and this was a scene he would rather not revisit.

As Byrne hefted their lone Innie prisoner over his shoulder, Avery motioned the other marines out the workshop to the waiting Hornets. Less than fifteen minutes after they'd dropped in, the two squads were clipped back into place. The Hornet's thrusters surged, and they streaked back the way they came. But this time they flew for speed, high over the volcanic plain.

The officers in the TOC briefly debated whether or not the drone circling the Jim Dandy should destroy the hauler if it tried to roll back on the highway before the marines arrived. The four-lane road was snarled with commuter traffic, and just one of the drone's Lancet micro- missiles was powerful enough to gut a main battle tank. Even an exact hit on the hauler's cab might touch off its tires, killing dozens of people in the surrounding vehicles. Far better, the ONI officer argued, to flatten the hauler in the Jim Dandy's parking lot. But Lt. Colonel Aboim was just as worried about shrapnel hitting the crowded restaurant.

Fortunately, the target individual spent the Hornets' twenty-minute flight eating a leisurely breakfast. According to the real-time feed from the drone's camera now mirrored in the corner of Avery's HUD, the man was just finishing his second cup of coffee when the Hornets buzzed up behind a smoked-glass, multistory office building on the opposite side of the highway.