The plan was fairly straightforward: evacuate everyone they could onto the Hephaestus, and immediately after attack the queen and her nest. Not to kill her or destroy it, though that would be a welcome accomplishment, but to buy time and keep her and as many of her brood busy and in place. The third part of the plan was simplest of all, just get Riordan to the secondary reactor in the station core. From there he could drop the bulkheads to seal it off, transfer his dead man's switch on the primary reactor to his daughter, safely aboard the Heph, and blow the core. It would almost certainly shatter the outer station, but the primary reactor room out there is the most structurally reinforced part of the whole station, so everyone who couldn't evacuate should be able to survive there until the Marines arrive in a few days.
Riordan's personal assistant, a synthetic called Adam, remains with him to make sure the systems all respond properly. He knows it means his destruction, but he's accepted his fate. This is what must be done to destroy the queen and her nest, to make sure none of the aliens get off the station. The suicide team keeps the aliens busy, Adam locks them in, Riordan blows it all up. That's why they're in the secondary reactor, moments from the end.
So why is Ramona there? The little synthetic has nowhere else to be. Everyone else that she cares about has died, most recently Shorley, her best and maybe only real friend. Declan Riordan is the last of her clients still alive and on station, and even though all she ever did for him was give him company at dinner and lay beside him while he slept from time to time, she's become very fond of him. So now, at the end of everything, she's there at his side to help ease his sleep one last time.
When the xenomorphs crash the evacuation in the docking bay, it's time to put the end game into motion. Riordan and Adam race through the maintenance tunnels, zigging and zagging on the wealth of the Overseer's knowledge of the station, heading to meet Ramona so they can finish this. Declan looks a hot mess, his hair sticking out in all directions, several days' worth of stubble on his jaw, his chambray work shirt rumpled and creased in all the wrong places. Adam, of course, looks perfect, without a hair out of place, the synthetic bastard.
The harried duo race through corridors, past grates that have been welded shut and sealed with hatches. The lights flicker on and off, as the battle in the Queen's lair goes down and vital things get hit with acid or bullets. Nearly there, Adam pauses. "Sir, we've received a communication from the Hephaestus. Your daughter is safely on board and they are away."
Riordan lets out a relieved breath, and some of the creases around his eyes seem to soften with the ebbing of tension. It's what he needed to hear to go through with this. Hannah is safe, or as safe as anyone can be after this fiasco of W-Y proportions.
They arrive at the station core in one piece, and climb out of the hatch. "Mona," Riordan says with a tired smile. He looks like he is definitely ready to go into that long sleep. "Is everything set?"
She's there, waiting for him. "I did everything I could," says Ramona, standing near the control console. She, of course, looks relaxed and unflustered, casually dressed and at ease. Synthetics don't get anxious. Sure, she's aware of the finality of the moment, that this will be the end for her, but what can she do? Where would she go? This is where she wants to be. Where she belongs.
Besides, it's not the first time she's died, even if it will be the last.
"Adam has to do the rest, and then you confirm the order." She offers a gentle smile and crosses over to Declan, going up on tiptoes and stroking his cheek. "Hannah's safe, and you'll be with your wife soon. You got the answers, Declan. You did good."
Declan smiles at the synthetic, tears glittering in his eyes but not falling. He pulls Ramona into his arms and kisses her, finally. Andfinally. When he at last comes up for air, he says quietly, "Thank you, for all you've done for me. And for being here at the end." Then he lets her go.
The Overseer moves to the console and signs in under his identification. "VULCAN, this is Overseer Riordan, Penumbra corporate ID DR-92756. Secure the control room." The bulkheads around the room come down, slamming into place, sealing the trio in.
VULCAN responds in it's disembodied computerized tone with, 'Control room secured.'
Riordan steps back to let Adam step up and type in the code to transfer the deadman switch to Hannah on the Hephaestus. Once the synth nods to him that it is done, he clears his throat. "VULCAN: Run command line, authorization DR-00001."
"SEALING CORE BULKHEADS," says the station AI, but it's not broadcast station-wide. They're taking no chances that those monsters can understand them. In a matter of a handful of seconds, the core is closed off. There's been plenty of time for the creatures that attacked the evacuation to get back once their queen and nest came under attack. All of them should be inside the core as it closes. Any left out of it? Are about to get vented when most of the station breaks apart in a moment.
"CORE REACTOR OVERLOAD IN TEN... NINE..."
Riordan feels Ramona squirm back into his arms. "He never held me," she says softly, head resting against his chest. "In all the many times... he never held me at the end. Please?"
As the countdown begins, Riordan's pulse races in anticipation of the coming oblivion. When Ramona comes to him again, his expression softens and he wraps his arms around her, kissing the top of her head, holding her tightly. "You deserved better," he whispers quietly. "You were too good for this world, Mona."
Adam stands stoically at the console, making sure everything goes smoothly, acting as the Overseer's assistant to the very last.
Everything has been calculated to be exact - too big of an explosion, you wipe out the station and Hephaestus entirely. Too small, it won't destroy the queen and her nest. Every factor was taken into account, and dropping the bulkheads serves more than one purpose, that of keeping the aliens in. It also blunts the damage going out.
"THREE... TWO... ONE..."
The explosion of Kolvek's suicide vest happens a few seconds before the big boom, and it's a good thing that it wasn't the entire plan because the queen and some of her brood actually survive his parting gift, albeit severely mangled. The reactor seals their fate.
From the Hephaestus they can see the sphere at the center of the station, the Eclipse resort and casino, the promenade, erupt in a sudden flash and a cascade of destruction follows as the station around it breaks into many pieces. Those inside the main reactor feel a wrenching shudder and hear alarms go off, but when the air isn't suddenly sucked out of the section, they know it held up. They're adrift in an enclosed chunk of the station, but they're alive and can be rescued.
In the following days, the Colonial Marines arrive, as does a Penumbra rescue vessel. Mr. Weyland never shows up, and The Company loudly and publicly denies all responsibility. Quietly, behind closed doors, they pay out a substantial sum to Penumbra and the survivors of the station and Hephaestus, and the families of the dead. Those who survived move on, return to their lives as best they can, and try not to let on that they have regular nightmares about pale, transluscent monsters and the friends and loved ones that were taken from them. They console themselves with the knowledge that it will never happen again.
Until one day, a life vessel is found floating in the outer rim, the sole survivor of the Nostromo safely in cryosleep within it.