Seven: Composer

The Mantle's Approach dropped out of Slipspace in an asteroid belt above a broken world, with magma boiling up through cracks in what remained of the crust. H 671 c "Quiescent" was so different from what he remembered that he almost didn't recognize it, but there was only one place that the Didact would go before he hit Erde-Tyrene – hit Earth.

[Cortana?]

'Still here,' the AI answered. She sounded tired.

He stood up, wobbling a little as his legs got used to carrying his weight again. [Installation Zero-Three,] he said, looking up at the curve of the ring, [where the Composer is stored. Why are we bypassing it?]

'Because the Composer's not on the ring anymore.'

There was a UNSC base on one of the largest asteroids, and the Didact and the Storm Covenant were heading straight for it. 'What are you waiting for?' she asked, 'That station's not going to save itself.'

John slipped down from his position and entered the Lich through the force field airlock. He killed every last alien inside, then moved to the control panel at the fore of the ship. [You got this?]

'I-I think so. But stay with me, just in case.'

The Chief slotted her into the console, monitoring her closely as she opened up communications with the outpost. "This is UNSC Master Chief to base. Do you read?"

"Yes! I hear you!" a panicked female voice came over the COM, "This is Sand Tillson of Ivanoff Station! We're under attack!"

"They're after a Forerunner artifact that you took from Installation Zero-Three."

"How do you know about that?!"

"Doctor," the Spartan said firmly, "I need you to protect that artifact until we arrive. Send whatever-" He sensed the beginning of a rampant episode and forcibly aborted it, suppressing the personality spike responsible. Cortana was afraid, but grateful for his help in maintaining control. "Send whatever troops you have to defend it. We'll be docking with the station momentarily."

"Okay," Tillson replied, "okay, I'll do it." The COM snapped off.

'I'm sorry – I just… can't stop them!' the AI whimpered as she docked the Lich with the station, 'It's like a thousand of me arguing all at once!'

[I know. It's okay, we can handle it.] "Doctor Tillson, are you there?"

"Yes, I'm still here! The soldiers are on their way!"

"Good. You need to issue the order for all civilians to evacuate the station." He sprinted across the landing bay, the doors opening at his approach. A security guard wielding a sticky detonator was killed by a number of Needler rounds, but the Kig Yar who killed him joined him in death when one of the sticky rounds exploded close to them.

"We've been trying!" the scientist told the Spartan, "The Covenant – they've already taken over the landing bays!"

"Send me your coordinates," the Chief ordered, "I'll see what I can do about clearing an evac route on my way to you."

The hallway let him out into a hangar. He saw a Jackal in the air and fired reflexively, killing it and saving the guard who was its intended target. The guard stayed back to protect two scientists while the Spartan advanced through the bay, gunning down a veritable multitude of Covenant. Yet no matter how many he killed, Phantoms swooped in to the hangar to drop off still more of the aliens. [What can we do to keep the Covenant out?] he asked over the gunfire.

'The Harbormaster controls can erect a barricade over the bay,' the AI reported, 'but we'll have to locate them.'

John did a quick scan of the nearby systems and located the panel on the opposite side of the bay, beyond a line of Grunts and Jackals. He threw two grenades into their midst, killing half their number and throwing the survivors into disarray long enough for him to sprint past them. He made it to the control panel, and raised the barricade before turning back to fire on the aliens.

With bullets coming at them from two different directions, it was inevitable that the aliens would turn their backs to someone who could kill them. And someone did, whether it was the Marines native to the station or the Chief supporting them. A side hatch slid open to disgorge more enemy troops into the hangar, but the Chief detected them beforehand and reacted in time to stop them from getting too far. He ducked past their corpses to aid a group of security personnel under fire from a plasma turret.

Two quick successive shots took the Grunt's legs out from under it, making it slam its face against the gun as it fell. A Field Marshal Sangheili shot it between the eyes before taking over its position at the controls. John was already firing on it, unloading round after round into its shields. The Elite fell before it even got off a return shot. The other Sangheili met the same fate, closely followed by the Kig Yar and Unggoy.

The Spartan moved forward into a wide stairwell, where additional guards were firing up at a handful of Grunts descending the stairs. He joined them, and they began to push up the stairwell. As they moved up, an orange scan wave passed through the station. 'Didact doesn't know where the Composer is!' Cortana managed, her voice shaky even inside his mind, 'Just that it's on the station.'

[The second I get a moment, I'm going to give you a boost.] He was supporting many of her subroutines, even running them for her, but the degradation was still happening, worsening every time she left his flesh. With all the chaos they were handling, he had no time to fix her failing processes, isolate and rewrite cascading errors in her coding.

'I'll be okay for now. Let's just get this done.'

He fought his way up the second flight of stairs it the uppermost deck in the bay. More ONI security agents were there, engaging a Field Marshal Sangheili and his support troops. John drew his sticky detonator and fired at the Elite, pulling the trigger again to detonate the charge. The alien exploded in a shower of indigo-violet blood and guts, along with a Grunt who got too close. The other Sangheili went the way of the first. John briefly grieved the fact that he was in his MJOLNIR armor and surrounded by UNSC personnel; it meant he couldn't infect the Storm Covenant, take their bodies for his own and make an army to fight the Didact on equal footing.

John continued heading through the halls to Tillson's lab. Just as he was getting closer to the objective point, he stumbled across a panicked scientist. "Help us!" she begged, "A pair of Hunters forced their way in! Take this. It's calibrated for heavy armor." It was a thruster pack, not quite as useful as a jetpack but better suited to the low ceilings of the base. It would aid him in evading dangerous fire he couldn't naturally dodge in time.

The Spartan entered the lab, already lifting his sticky detonator to lock onto one of the Hunters, following the phantom projection of his "anticipation." Two of the projectiles were sufficient to kill the first of the Mgalekgolo. He turned to the second even as it turned to him, its fuel rod gun charging. John was about to dodge out of the way when he realized that there were two civilian scientists huddled against the wall behind him. If he moved, they would be killed.

He gritted his teeth just for a moment, then loosened his jaw, ducked his head, and crossed his arms in front of his head to take most of the force and prevent him from getting a concussion from a fuel rod charge to the face. The impact dropped his shields to zero instantly and sent him skidding backwards a few meters. He dropped to one knee and planted a hand against the deck to maintain his balance as he returned fire, his vision unfocused and senses in disarray.

But his "motion tracker" sense – and by extension, his aim – held true. The Hunter fell, leaving the lab clear of enemies. John sank to all fours, panting and sweating from the heat of the fuel rod charge, his shields screaming in his ears. When his limbs stopped shaking, he got to his feet, staggering a little. One of the scientists he had just saved approached him, carrying a large canteen of water, and offered it to him. "Thank you," she said, and held his helmet while he chugged the entire contents. He felt Cortana's fascination with the sensation and taste, and took a step back to allow her a few pulls.

Then they nodded their thanks to the scientist, pulling their helmet back on. 'Tillson's behind the door over there,' the AI said, throwing up a nav point over the door controls. He hit the switch, and the barrier slid open to allow him inside.

Sandra Tillson was waiting almost immediately inside the doors, and greeted him nervously. "I desperately hope you know why all this is happening," she said, leading him further into the room, "because, to be honest, my objectivity isn't doing me a whole lot of good right now. Hold on, I'll start us down."

John waited until they were moving, then said, "The device you recovered is a Forerunner weapon. They commander of that ship wants it back."

The scientist paused and turned back to him. "'Wants it back?'" she repeated, "You don't think you can remo – it can't leave the station, you know that, right?"

"We don't have any choice, Doctor."

Tillson shook her head. "It's not a matter of choice," she said, "It took three months, and the biggest starship the UNSC could throw at it just to relocate it here." She waved at the Composer as it came into view. "Unless you're a lot stronger than you look, it's not going anywhere."

She was right, but leaving it as it was, wasn't an option. The Didact could not be allowed to reclaim the Composer, and with the FoS not even in the galaxy (which, what the fuck were they even doing extra-galactic?), there was only one option left to them. "Can you give Cortana access to the station's supply manifest?"

The scientist did so, tapping a few keys on her console. "What for?"

"If we can't move the Composer," he answered, "we have to make sure the Didact can't either."

Tillson caught on fast. "We have years of research invested here," she protested, but there was nothing he could do to help her. If his fleet still had the Parallel Composers, perhaps he could arrange for her and her team to do a limited study of one of them if they survived.

"Inventory lists seven excavation-grade HAVOK mines," said Cortana, "Just one of those would turn this base into a piñata."

The scientist looked at him, pleading wordlessly.

"I'm sorry, Doctor," he said gently, "but with the kind of damage the Composer can do and the scale of it, we can't afford to let it fall into enemy hands, the same way the UNSC couldn't let the coordinates for Earth fall into the hands of the Covenant during the war.

"Keep routing your people to the evac centers. Once we take care of the Composer, you won't have much time."

The civilian was unhappy, but she understood. "I'll… make sure the nukes are primed so you can… detonate them remotely." As he turned to go, she said, "Maybe next time you rescue us…"

The Spartan turned back to look at her.

"…you can give us more time to pack?"

"Next time," he said with a nod, and exited the research lift. The hatch on his left was nonfunctional, sparking with electricity, se he went right instead, and entered the chamber where the Composer was being kept. The Chief went straight for the device, admiring the Forerunner construction as he approached it and laid a hand on its side.

/BIOSIGNATURE RECOGNIZED: SPRM CMDR (FOS) UNSC SPARTAN JOHN-117

/REQUEST ACKNOWLEDGED. BEGINNING DOWNLOAD…

/ALERT! VIRAL CODE DETECTED!

/COMMAND OVERRIDE: VERIFIED. RESUMING DOWNLOAD…

/DOWNLOAD COMPLETE. INSTALLING…

/INSTALLATION COMPLETE.

[That'll slow him down for a while,] John said, pulling out of the Composer's systems. As he did so, an explosion rocked the station. "Doctor, what was that?"

"The Covenant…" the shocked scientist managed, "The Covenant just shot down the first evac shuttle."

"The station should be equipped with outer turrets. If we can reactivate them, I can program the station's defenses to provide cover for the evacuation," Cortana piped up.

"Okay… Okay, I'll send you the coordinates."

Once she had them, Cortana set up an objective point to direct him. Inside a hatch, a security guard was sitting down, taking a breather from a fight. As the Spartan approached, the guard got up and keyed the control panel for another door, opening it for the Spartan. "Officer, seal the door behind me."

"Yes, sir."

John moved through and up a catwalk to the hallway above. As he did so, another scan passed through the station. The Didact's mind pressed in again. 'You impress me, Abomination. Your singular valor will be preserved and studied, once your Composition is complete.'

[How about no.] The hybrid intended to reach out and strike at the Forerunner, but the station shook under him, the power flickering out, forcing him to refocus on his immediate surroundings. There were two aliens nearby, a Grunt and a Jackal, that he quickly took out. The hatch behind them sealed itself between the Spartan and his next targets, a pair of Jackals further down the hall. There was a service tunnel close by, and he ducked into it to bypass the lockdown.

The hall opened up into an airlock loading zone filled with Covenant. He threw a plasma grenade and stuck the Sangheili before it could fire on him. The alien screamed and died, along with two Grunts that were too close. The rest of them were just Grunts and Jackals, no Elites – until they started coming in through the airlocks. John used his "anticipation" to track their movements and kill them quickly so he could move on.

The Chief ducked through another hatch, sprinted down a catwalk, and into another hallway, where a group of scientists were pinned down by the Covenant. The Sangheili leading them had its back turned to him, letting him dart in and climb up its back to knife its neck. The corpse fell as he pulled his blade free and went for the Kig Yar, yanking the alien around and plunging the blade down through its skull. A single shot between the eyes took care of the Unggoy.

The Spartan ducked into the chamber to talk to people inside. "They ran!" one scientist cried, crying and holding a Magnum with shaking hands, "The security team assigned to us, the second the Covenant showed up! How could they do that?!"

One of the other scientists keyed open another hatch, letting him into a side chamber as the other spoke. "Find Doctor Tillson," the Spartan told them, accepting the autosentry he was handed, "She'll direct you to the evacuation area."

The sole remaining guard and his civilian charges did as instructed and headed back the way the Chief had come. The Spartan himself continued on, moving through the main hall and up a catwalk into another airlock loading zone. Like its predecessor, it was also filled with aliens, with more coming in through the airlocks themselves. John launched a grenade into a tight knot of them, and fired at the first group coming out of the airlock. A number of aliens screamed and died in the satisfying explosion, leaving John free to focus on the newcomers.

There were a couple of Jackals overhead, sniping at him with carbines from maintenance platforms. He slipped up a maintenance ramp and shot them, then rained fire on the Covenant below as the rest of them came in through the airlocks. 'Only a few more left,' Cortana murmured, marking them on his HUD. Once they were dead, the lockup was lifted, and he moved on to the next hall.

As he did so, another scan passed through the station. 'Maybe the Great and Powerful Didact shouldn't misplace his things!' the AI hissed.

The hatch in front of them slid open. The Chief sensed the Spec Ops Elites before he saw the distortion of their active camouflage. That explained why he couldn't remotely activate the defense systems – they were being manually overridden. He fired at the alien at the console first. It roared and turned to return fire just in time to catch a sticky grenade to the face. The Spartan was already firing on the second alien, who was charging him with a plasma sword. He ducked the first swipe, punched the Sangheili in the face hard enough to bring down its shields, and damn near crushed the alien's wrist keeping the sword away while he unloaded an entire clip into its chest cavity.

As he moved toward the console, Cortana slipped back into his armor, preparing for insertion. Unfortunately, that also meant that her personality spikes were back in full force. "My intervention is the prerequisite for success!" one cried, before another hissed, "Why should we save them?"

John slotted her in, calling for Tillson over the COM. "I'm here," the scientist answered, "Any luck?"

"Cortana's bringing the defense grid online now," he informed her.

"I hear it," she said as the guns began firing, "We'll broadcast the final evac orders."

"The nuke?"

"We're rigging it now. Meet us back on the upper platform, and we'll help you get it to the artifact."

The COM shut off. He pulled Cortana out of the system and back into his flesh, wincing a little when the personality spikes fought him. But he was a full-fledged Gravemind in human form – they couldn't do any real damage to him. 'Chief?' Cortana whispered, 'If we – pull this off, and actually get back to Halsey? Don't tell her how bad I got. Please?'

[I won't say anything,] John promised, and headed out through the hatch opposite the one he'd entered.

As usual, there were Covenant in his way. He fought his way through the halls and passageways, finally reaching an observation deck overlooking the Composer. There were no still living humans in the chamber. Instead, multiple Phantoms swooped overhead, while aliens below cheered and worshipped the device. 'Keep them away from it!' Cortana cried, 'Stop them, Chief! You can't let them tell him it's here!'

The Spartan headed out into the main chamber and sprinted for the nearest Mantis. "Doctor Tillson, the Composer's location's compromised," he said, climbing the back of the machine, "You've got to get that nuke down here!"

"I-It's not ready yet!"

"Ready or not, I need it now." He felt bad for snapping at her, but he had no time to cater to civilian sensibilities. The Chief narrowed his focus from tracking movement and transmissions through the entire station down to the chamber with the Composer, and spread his mind out into the Mantis and a number of automated defenses in the room. Wave after wave of Covenant soldiers slammed into him, trying to overwhelm his defenses with infantry and vehicles alike. Grunts with fuel rod guns, Jackals with carbines, Elite with Ghosts, Wraiths, and Banshees all bore down on him, but to no avail.

"Doctor Tillson!" John called as he shot down a fleeing Phantom, "Where's the warhead? Doctor Tillson!"

'Head back to the elevator platform,' said Cortana, 'I'll keep trying to raise her.' She sounded anxious, with a faint edge of hysteria.

He guided the Mantis over to the platform and hopped out, sprinting for the hatch. When he entered the lift, the AI said, 'The HAVOK mines'll be in one of the cargo bays. Start us up.' He tapped a few keys on the console. The elevator groaned and began its ascent. As the Composer came into view, John sensed something that made every hair on his body stand on end. He threw himself backward as Cortana cried, 'Chief! Immense Casimir wave building outside the atrium!'

The roof of the cavern was ripped off with the shrieking grind of rending metal. One of the cranes nearby was torn free of its mount and smashed into the lift, throwing them to the floor. The Chief covered his head to protect them from the debris shrapnel, his hands automatically covering the slot where Cortana's chip inserted into his helmet.

The crane fell away with another jolt. John pushed himself up to see what was happening, right before a brilliant orange tractor beam ripped open what was left of the base. The Composer eased free of its moorings and was lifted out of sight. [Cortana, see if you can raise Tillson. Get me a status on the rest of the station.] He himself moved to the damaged console, trying to get the lift restarted.

'Tillson, Sandra K,' Cortana said dreamily, struggling to process even with his help, 'Female, 51 years of age. Doctor of Archaeology, Pegasi Institute-' Her voice turned strained. 'Got her! Biosignature stable on 350-level, B-deck.'

[Thank you, Cortana.]

The elevator resumed moving, then stopped. John hit the manual release for the doors, and sprinted through the halls until he spotted Tillson in the milieu. "The Didact's taken the Composer," he informed the scientist, moving to a nearby holopanel and slotting Cortana in, "Get these people to the evac centers!" To the AI, he said, "Tap the flight deck. Find us something that can carry a payload."

John didn't hear the scientist demanding to know how the Composer had been taken. He was entirely focused on aiding Cortana's processing and observing the Mantle's Approach drawing closer to the station. The Composer was beginning to charge.

[Three… two…one…]

Without warning, the Forerunner ship shut down. The Spartan didn't need to be present to hear the Didact's cry of rage as the viral insert did its work, wresting control of the ship from the Promethean. It wouldn't hold for long, but with any luck, it would hold just long enough. He allowed himself a small vindictive grin, then squirmed into the systems to join Cortana. [Focus on finishing prepping the nuke and getting us a ship. I'll handle the defenses.]

The mini-MACs set up around the station perked up as one, and swung around to aim at the Mantle's Approach. Only a handful of them had a direct shot on the Composer, not nearly enough to destroy it, but a larger number of the turrets had a line on a section of the ship where the plating was thinner. The rounds punched through the hull and destroyed some internal components, silent explosions flashing out in space. John managed only three more volleys before the Approach came back online, but it seemed that was enough to convince the Didact that it wasn't worth the effort to try to take the station while he was there. The damaged ship began creeping away, slowly, painfully. It seemed he damaged some of the propulsion controls.

"Let's go. There's a Broadsword waiting for us in Hangar C-11," said Cortana aloud, purely for the benefit of the scientists around them, "If we hurry, we can catch him."

On the way down to the hangar, John cleared out what was left of the Covenant forces, but more often he saw weary guards and scientists, carrying injured or dead friends and comrades on makeshift stretchers. Their grief permeated the air. 'These people are gone,' Cortana whispered, wanting to stop and help but also knowing that wasn't an option.

[And more will follow if the Didact reaches Earth.] Because that was undoubtedly where he was headed.

The hybrid could sense the train of the AI's thought. She felt that she hadn't done enough to support the Spartan and help the station, which led to – 'They'll pair you with another AI,' she whispered, 'Maybe another "Cortana" model if Halsey lets them.'

[That's not going to happen.] His voice was just as quiet as her own, but firm and resolute.

'It won't be me,' she whimpered, despairing, 'You know that, right?'

[Cortana.] When he had her full attention, he continued, [It's not over. Not yet.]

'Not yet,' she repeated.