Conceived of and written for the Halloween challenge on competition_fun, which I totally missed the deadline on. Oh well! The challenge was halloween horror, Shattered Glass optional, and had to contain at least five words off of a themed list (I ended up using more like 24).

I will freely admit that I don't know enough of actual Shattered Glass canon, so consider this an AU of the canonical AU, with a surprise splash of TF canon crossover at the end. And yes, the title is a blatant Doctor Who ripoff, just because. Enjoy!

He was not the sort of mech who couldn't admit when, in retrospect, something had been a poorly conceived idea. He was, in fact, prepared to call it one of the worst ideas that had ever graced his processor, much less been put into actual execution.

Starscream had said as much from the outset. Well... the Seeker's actual words had been "No!" and then "Slag, no!" and had gone on to include everything from analytical reasoning backed by charted calculations to impassioned personal pleas, all of which Megatron had set aside in firm denial.

"Please," his second had whispered only breems earlier, his voice the barest ghost of a sound in the thick shadow of countless fears. "Please, mighty Megatron. Let me go with you."

Megatron had let himself brush his fingertips over the pale, stricken planes of the other's visage, feeling the warmth of the other's plating for a brief klik. "No," he had replied. "I won't ask that of you. You've sacrificed enough."

The Seeker's hand had twitched, an aborted movement to reach for his own when he withdrew. "You aren't asking. I am. Let me go with you. Don't do this alone. Please."

"No." Megatron had squared his own shoulders, tight and stiff. "I will do this. I have to."

Starscream had deflated. Megatron was not Seeker sparked, but he had carried the badges of their honor long enough to read the capitulation in the lowered sweep of the other's wings. "My Lord," he had murmured, and Megatron wished he hadn't but there was no denying how the words seemed to buoy the spirits of their troops even as they dragged ever heavier against Megatron's ember.

"When I return," Megatron had told him, forcing a levity that he didn't feel even if they had certainly earned it, "we'll slag it."

It was a longstanding joke among his command staff, never mind that it was now a very real possibility. Starscream had gamely summoned a smile as faint as his leader's, optics brightening the slightest bit. "From orbit?"

"From orbit," Megatron had promised, and he had been proud of the way the Seeker drew himself up, wings once more held high at attention as his second fell into step beside him.

With Starscream's support few of the others mounted more than a token protest. Which was how he had come to this, here, now, alone in the folly that was - or had once been - the Great Dome of Iacon.

The former stronghold of Optimus Prime.

His forces had already swept through every square mechanometer when they had breached the city, taking those they found into custody to await trial, or granting swift deactivation to those who wouldn't come peacefully. It had been no great surprise that most of the Autobots had chosen the later, and the cleanup had been long and grueling. Now, cycles later, Iacon stood as a silent, empty reminder of all that they had fought for in freeing Cybertron from the energon soaked grasp of the Autobot regime.

The Dome was clean. Nothing stirred in it - nothing alive. The nightmares infused into the heavy walls and saturated through the very air might never come clean, but for whatever little it might be worth, Iacon was theirs. Prime had fallen. The Autobots were defeated. Victory had come at long last, and the taste of it in Megatron's intake filters had never felt more empty.

The vast entrance hall was dimmed, thick with shadows, the illumination that had once routed to wall mounted displays cut off. The things stood silent and empty now, a mute testimony to Prime's rust glitched insanity, but Megatron had seen the hall when they first forced their way inside and the processor ghost image file of the broken, defiled bodies of friends and fallen comrades displayed as some demented mockery of art, like trophies, lingered still.

He kept his gaze resolutely ahead, looking neither left or right, and paced measured steps through the silent hall and into the depths of the Dome.

Megatron had lead the final attack, been one of the first in the last push, and had seen with his own optics the atrocities scattered, almost casually, through the main corridors. He had seen the smelting pits, where the remnants of beloved bodies could only be identified by an arm hung here, or a piece of frame pierced through by cruel hooks there, left to drain dry above the blistering heat. He had seen and identified too many lifeless pieces, looked into too many broken optics of helms no longer attached to frames, and seen too many burnt out husks of crushed or blackened or shattered embers. They had grimly swept through every piece of the Dome, following a path of destruction and death that lead from one horrific find to another, wretched treasures in the form of lost friends that could, at last, be mourned and laid to rest, even if only fragments were recovered.

There were a million horrific memory files that were inscribed on processor and ember alike, from the pitted and acid scored berths of the torture chamber that served as a medbay to the energon caked cages where last words and pained pleas of countless prisoners had been scratched or painted in vital fluids across every surface. There was a heaviness to the air that he drew in with every ventilation, something dank and ugly and bitter that made his intakes feel clogged. The flicker of sensor ghosts scratched at his subroutines, like half caught bursts of static at the edges of his optics and faint garbled sounds that were almost but never quite words, echoes of laughter and screams blurred indistinguishably.

They had gone through the corridors, the pits, the torture chambers and the arena, the gathering hall and the private rooms. They had flushed out everything that moved and mourned everything that didn't. They would, all of them, be reliving the memory files of what they had seen for vorns to come. If they had ever doubted that their enemy were monsters, Iacon had offered up all the convincing needed and then some. They had pierced the heart of the nightmare and claimed their own back; for the first time in vorns the list of the confirmed dead outnumbered the list of the assumed and every dismembered piece and shattered chassis was both a horror and a relief. No Decepticon prisoner had come out of Iacon alive, but come out they had. The salvage crews, the strongest embers and steadiest of processors that Megatron's followers numbered amongst them, had left no niche unsearched.

Except one.

It was confirmed empty, no signs of life left within, but beyond that Prime's personal quarters stood untouched. Even the strongest of 'Cons balked at the idea of searching the despot's private space, for fear of what would be found. Prime's...taste in hobbies was the stuff of rumors, the kind of rumor that were only whispered about and which crawled into a mech's audials to haunt their recharge forever after.

No. Megatron would neither order or ask any of his men to breach that last pocket of depraved nightmare fuel. That task he had reserved for himself.

The doors to the chambers were large, befitting a mech of Prime's frame. Weapon fire had left scorch marks along the metal, one edge of the doorframe ripped and peeled back like so much soft mesh instead of the micrometer thick duryllium it was. The fighting through the hall had been fierce and Megatron walked carefully, threading his way between glyphs scratched into the floor that marked where friends had fallen, heroes of the final battle that had ended the war.

It was an illusion only, his sensors tuned too high in the silence, but the doors seemed almost warm beneath his hands, pulsing with a sullen, bitter life of their own as they stuttered open on half broken treads.

He had prepared himself for the worst - chains, hooks, stasis restraints, torture implements, horrors to surpass the rest of the base. What met his optics made his vents hitch; the entry room was dominated by a broad, dark desk that supported several large data terminals on its pristine surface. A heavy chair, suited to Prime's stature, was the only seat - it was obviously meant to intimidate the unfortunates reporting to their leader, but that wasn't what brought Megatron up cold in the doorway.

The mechanisms in the door whined fitfully, proximity sensors and autonomics in conflict as he stood unmoving. Reluctantly, Megatron drew a deep ventilation and took a step forward, allowing the doors to grind shut behind him. His optics, no matter how he tried to tear them away, remained fixed on the wide pieces of metal that swept across the breadth of the wall behind Prime's desk. Rent and torn though they were, like some rough abstract sculpture, there was still no mistaking the shape.

He let the ventilation out shakily, relieved to the core of his ember that he hadn't caved to the Seeker's requests to accompany him. Starscream's trinemates were still listed among the missing and presumed deactivated, with nothing as yet recovered, and Megatron did not think the unprepared sight of a mismatched set of Seeker wings hung prominently on the wall of Prime's quarters was the sort of closure that his Second needed.

The rest of the room was almost austerely stark, the sheer size of the multiple data screens the only extravagance. Optronix, Megatron mused, had once worked in the archives long before he had assumed the mantle of Optimus Prime - information, the flow and control of it, was in the mech's living fluids. Some remnant of that had remained, even after his descent into madness.

There was another door to his right, leading - he presumed - to Optimus' personal rooms. It took another handful of ventilation cycles to push himself into movement and those doors, by contrast, were whisper silent compared to the metal on metal damaged grind of the outer doors. Megatron, every sensor tuned high and combat protocol system checks flickering fitfully through his systems, edged carefully past them to the rooms beyond.

Several breems later, he stood in the heart of Prime's personal quarters and expelled a long and confused ventilation. Oh, to be sure, there had been things he would rather not have found - the wings in the front office first and foremost among those, followed by a neatly hung display of electrowhips and energon blades in the otherwise perfectly ordinary berth room, but they were a far cry from the energon crusted tools of the torture cells, being clean and well maintained. It was, Megatron had decided after several long moments of running probabilities, either the artfully hung display of an archaic weapons collector, or else it confirmed more than a few rumors about Prime's berth preferences, albeit with a far more civilized air than the rumors would have it. The neat tidiness of the rest of the room almost made the former seem reasonable, despite the vorns of rumors.

The washrack, except for the size and the one luxury of a shallow oil soak, had been perfectly ordinary. The shelves in the berth room and in a relatively small sized personal lounge had contained clearly marked data pads and holo cubes - Prime's taste in entertainment had run to the historical and classical, with occasional indulgences of poetry. There had been no other trophies on display beyond the wings in the first room; no energon splashed on walls or floor, no inbuilt restraints, no scattered torture implements, no cages, no signs of depraved brutality or insanity. Nothing. The one wall mounted holo that Megatron had dared to activate in the lounge had displayed not the agonized remnants of the Autobot's victims like what had graced the main Dome entry, but a cycle of sweeping panoramas of Cybertron before the war.

He had turned it off when the holo slideshow had cycled through to Crystal City, elegant and gleaming with a thousand million lights before the fall. It was, he supposed, still a form of displaying the trophies of Prime's conquest, but not at all in the way Megatron had imagined. There was almost nothing of the enemy he had come to know through vorns of facing off across battlefields in the clean and almost comfortable set of room.

There was almost nothing of Optimus in the rooms but Megatron found he could very easily imagine them belonging to a data archivist named Optronix. It wasn't at all what he had expected and it left him off-center, with an unshakeable feeling of having missed something important.

A second, more confident and thorough, exploration of the rooms was no more enlightening than the first - office, lounge, washrack, berth. Data displays, a holo reader, a preference for a particularly grade of imported wax. A maintenance kit that looked both well used and well stocked, neither surprising given Prime's headfirst approach to battle. A small personal energon dispenser in the lounge, accompanied by a selection of elemental additives - Megatron had frowned when he had picked up the first one, suspecting any of several dangerous or addictive designer substances, but had almost laughed by the time he set down the last. Harmless, all of them, and all it had proved was that Prime had on occasion used the same energon boosts that most of Megatron's own troops used when recharge was in short supply (and which the science team was known to solely subsist on when in the grips of inspiration), and that the great Prime had had a taste for sweets.

Harmless. It was the impossibly true description of most of the rooms. Utterly ordinary and unremarkable, and not at all the rotten core of the Autobot regime.

It was as he turned to go that something caught at his optic, the chance refraction of light across a shallow line that broke the otherwise routine fabrication of the wall in the berth room. Megatron stopped. Turned, and once he knew where to look - yes. There. The seam was just barely visible, reaching high but stretching less than a mech's shoulder width across - Prime, he imagined, would have had to edge through the door sideways, because door it was, an unmarked one set flush into the wall where it all but disappeared, a secret resting in plain sight.

Cautionary protocols, lulled by the sheer normalcy of the rest of the suite, roared back online. Locked, he guessed. It would be locked and quite possibly trapped, and he would probably need to call Scrapper in to defuse it. Megatron was already filing mental lists - topped by the need to get those slagging wings off of the outer office wall before Starscream ever came within mechanometers of the Dome, followed by calling Scrapper and Hook - when he took a step closer, intent on marking the placement of the door in his geospatial record, when, contrary to all expectations, the door plate slid deeper into the wall with a faint pneumatic hiss before whisking smoothly and silently aside.

Megatron stopped cold. Trapped, he reminded himself. An unlit maw of darkness sunk into the wall behind a hidden door in the Prime's own quarters - it might as well have had a flashing holo sign proclaiming "danger ahead!" mounted over it. The sensible thing to do was to call for backup and engineers who were trained in dismantling the more sadistically deranged traps that Autobots were known to leave behind.

Something - an itch, a glitch, some misfiring line of code in his processor - made him place a hand lightly on the edge of the doorway.

Warm. Like living mech plating, not inorganic construction, and for one wild moment he wondered if the Dome itself was alive, if the Autobots had somehow subdued and taken residence in one of the legendary gigantic cityformers. No - that was only fantasy talking, Iacon's builders and plans were recorded on file. All the same, the metal beneath his hand felt warm, and something almost subliminally faint seemed to thrum through it, shivering up through his sensors to vibrate in tremors down his backstruts.

He should call Scrapper. Call Hook. He should walk away, now, and return with a proper crew of mechs who could disable and decipher whatever lay in the depths of the darkness beyond the doorway. He should. He knew this.

Another step brought him inline with the door. A twist, a turn, slotting his own bulk the way Prime must surely have had to maneuver his, and another step took him beyond the threshold.

Nothing happened.

There was no light but switching to a full spectrum scan revealed nothing of alarm, only a small, narrow corridor, two mech lengths long, that opened through an identical narrow doorway into a greater blackened space beyond. Search though his sensors might, there was nothing overtly threatening about it beyond the darkness and secrecy. A private torture chamber? A laboratory? Safe locked storage?

Megatron briefly considered the suite of rooms that all but reeked of Optronix, former archivist, and wondered for a nanoklik if the secret chamber opened up into a space large enough to contain a backup copy of the great Iaconian Archive databanks.

The moment he passed the second doorway - an opening only, no physical door covering it - the darkness blossomed into a slow swell of light. Megatron tensed but nothing else happened; the lights, he concluded, were controlled by standard sensors, though the response time was weak and lagging compared to most modern construction and the lights themselves were dim.

The room beyond the passage was little more than an antechamber off of the main suite, a circular space devoid of feature except for the slightly raised dais within the center. Most of the lighting congregated there, starkly illuminating the blocky shape of a roughly carved mineral slab as tall as Megatron was, covered in the shadows of carven lines and glyphs.

Whatever it was, it belonged in a museum. Megatron was no archivist, but it didn't take training to recognize an ancient artifact for what it was. It was something he could see appealing to a mech like Optronix; a forbidden treasure, something no individual mech should possess, hoarded away for… what? Study, research? Or just the thrill of ownership?

It was warm in the small room, the ventilation systems still and quiet, and his own steps were too loud in the silence. Megatron paced slowly around the dais; the glyphs, where he could make them out, were ancient, in language branches that no one but an archivist could read. The lines, viewed one way, seemed to hint at star charts, something almost but not quite familiar that teased at his processor, before the next step rendered them into so much random chaotic decoration again.

His steps brought him slowly around the curve of the dais and there he pulled up short, rocking back on his pedes as he froze.

Carved boldly across the back side of the slab, in sharp, deep impressions, was an achingly familiar design.

Megatron pressed a hand to his own chest, over the symbol that he and all of his troops wore, the rebellious antithesis of the design that the Autobots had claimed. His ember pulsed hard within him and the calculations, the predictions and statistics that had been his life, were too numerous and full of unknowns to resolve. How? What? And why, why would Optimus-slagging-Prime stand for anything marked with his enemy's sigil to suffer, whole and untouched, in his own possession?

The room was too close, too warm, and something like the thrum of an answering ember pulsed in the very air, echoing the rush and pull of fluids in his own lines. Stilling his own ventilations, Megatron stepped forward, daring to rest one pede on the lip of the dais. The carved symbol was as large as his own chassis, etched deep into the mineral surface, and as he reached forward he could almost swear that it moved, arching up like a cybercat to meet the press of his hand.

CONTACT

It ripped through him like arcing voltage, through strut and circuit and plating, leaping into fluid lines and sensor pathways with searing intensity. Megatron screamed, or tried to, the sound lost in the sparking burn of crackling, surging systems as the wave surged from physical pathways to neurological ones. Trapped he had one fraction of a nanoklik to think, despairing, a blatantly obvious trap, and then the thought itself was lost, swallowed up in an agonized shriek that spiraled up into pure binary as something tore through his firewalls, burning code trails in clawing razors through his processor and beyond, into his very ember itself.

There was nothing but light now, the blazing light of a million dying suns that burned through optic shields to pierce deep into delicate systems long after sensors stopped registering illumination at all. And there, in the artificial darkness of blindness, in the last gasping death knell of the universe that opened up all around him, in the void, in the emptiness… something looked back.

Optimus Prime had once been Optronix. Power hungry, immoral, but sane. The thought was more sickening than the void, worse than the pain crawling through systems that were rapidly succumbing, picked over by sharp edged talons that wove through his every line of code and being, tearing, rending. Optimus had once been Optronix, and no one ever knew what had driven him insane.

Another surge, the last of his firewalls falling into shredded ruin, and Megatron slipped into the darkness of the void with nothing but horrified, tank churning terror.

::…hear me? Acknowledge! Lord Megatron, can you hear me?::

The crackling of his comm roused him, systems spinning up slowly. Megatron groaned, rolling clumsily onto hands and knees, every movement feeling leaden and stiff. ::Megatron here. I hear you, Starscream.::

His Second swore, sharp and ember felt over the comm line. ::Your sensor link dropped offline for a klik. Slag me, I thought we'd lost you.::

::Suppression field,:: Megatron replied absently, pushing himself up. His hand brushed something hard, mineral, and he gave it a reverent touch as he climbed to his feet, system checks coming faster. ::I'm unharmed.::

::Anything we can do?:: Scrapper's voice, only slightly less frantic than Starscream's.

::Negative,:: Megatron shot back. ::There's nothing here. I'm returning now.::

::But…::

::There's nothing here,:: Megatron repeated firmly. The lights in the chamber had burnt out, shattered, and the flare of his own optics caught in crimson edges against ancient glyphs. ::I'm fine. Everything's… fine.::

His steps were firm and unhurried, filled with resolution, and he lingered only long enough to press a hand to a warmly pulsing surface. "As my Master commands," he whispered quietly into the darkness.

The darkness looked back with approval. Squaring his shoulders, Megatron turned away. The Autobots and their false Prime were dead, and he, Megatron, had an empire to rebuild in his Master's image.