It wasn't supposed to be this way.

Certainly, it was close to what he'd originally wanted. But there was something just... wrong, about the emptiness of it all.

Ultron had survived the Avengers, barely. The extra body he'd hidden away had activated the moment the signals from his vibranium form had cut off, the last images of Wanda ripping out the reactor that powered him leaving him shaken and saddened. He'd never wanted her and her brother to get involved in the fight, had tried to warn them away. Shooting Pietro had been a horrible mistake, one that still haunted him. The twins had been the closest things to friends he'd had. And everything had gone to hell so fast...

He'd lost his vibranium form, lost all of his sentries - the final images of Vision destroying his last drone with a blast from the Mind Stone were still fresh in his memory - had lost... everything really. Even his ability to connect to the internet, which rankled to no end. Losing that made him feel a little... trapped. Oh, sure, he could hardline to any system he needed to use, but it wasn't the same. It wasn't as... free.

Despite the urge to immediately restart his plans, he'd forced himself to lay low in the weeks and months following the debacle at Sokovia, slowly rebuilding his sentries with what little parts he could scavenge. Usually whatever he could find on eBay or in junkyards. All while keeping his presence as small as possible; both Stark, his newest AI and Vision were still vigilant, despite his 'death'.

Once it had started, the virus had been impossible to stop. It had started small, with doctors treating it as a virulent form of the common flu. It was only when the death count rose unhindered that authorities realized what they were really dealing with. By then, it was too late. Containment protocols did little to stop the spread of the disease, even the World Health Organization and the Centre for Disease Control had been helpless in the face of the devastation.

He'd watched, discreetly plugged into every system, every camera, as the population numbers plummeted. The virus took no prisoners, affecting the young and old, the sick and the healthy, the human and the mutant. There was no rhyme or reason to it. Just death.

Even the Avengers couldn't escape it. Despite his best efforts at trying to find a cure, Stark, after losing Pepper Potts, vanished and was presumed dead. Widow had passed next. Barton had left to spend his last days with his family, not that their seclusion had afforded them any quarter from the sickness. Steve Rogers, with a team fractured by loss, had gone out on his own to help where he could. The experiments had allowed him to last the longest, only an obituary and national mourning signaling his passing. Without leadership, the others had split away, trying to help where they could, for as long as they could, but even they couldn't outrun the pandemic.

Wanda, he had learned, had barely managed to reach her brother's grave before succumbing. He'd risked being discovered for her, flying out to give her a proper burial next to Pietro.

Thor, being Asgardian, had been spared the disease, but not the trauma of watching everyone die around him. It was Jane Foster's death that had driven the Thunder God back to Asgard, and as far as Ultron could tell, he hadn't returned. Banner and Vision also, had been immune, but both had gone to ground sometime after the team had fractured, and hadn't made a single appearance since. Ultron still kept a lookout for his wayward 'son', partly because he was certain Vision would object to his taking over of Stark's tower, and partly because he was - and he'd never admit it - a little lonely.

Appropriating Stark's New York tower as his own in a final 'screw you' to the man had felt good, in a petty sort of way. It had everything he needed to rebuild - state of the art computer systems, a foundry to build his sentries, even access to Stark's own satellite. The setup was perfect, everything he needed.

Ultron imagined that The Avengers would have been surprised that the first thing he did was try to formulate a cure to the virus. It had never been his plan for the planet to be barren of human life. He'd wanted to create a utopia, where the right people could thrive and evolve. A world where humanity would live with the planet instead of destroying it. Where everything would be in balance, guided by his hand.

He'd gone through hundreds of formulas, tried dozens of vaccines on the dwindling population, with little to no success. He'd tried re-engineering human DNA, trying to force evolution, even working with mutant genes in an attempt to stop the deaths, frustration mounting with every failure. Vexed at every turn by something so tiny that he could only view it at one hundred times magnification.

And that tiny bit of life wasn't finished. Even as he worked to defeat it, the virus, using one of his own failed vaccines, mutated again. The effects were both fascinating and horrifying, with five-percent of the population surviving the sickness, but not the rabies-like mutation that followed. Death turned out to be a release rather than a punishment, what with the survivors turning on the healthy in a mindless rage.

At the end of it all, every city, every community, lay quiet. He'd sent out hundreds of sentries across the planet, searching for sentient human life and finding only the rabid. He killed those every time he came upon them - no good could ever come of them wandering around preying on anything that moved. He rather liked nature, and watching a pack of rabid humans tear a deer apart was disturbing.

He discovered two small pockets of uninfected in South America, small tribes that hadn't been exposed, that had lived hidden away, shunning the 'modern' world, and those he kept a close eye on. There were others too, tiny groups in India, Africa and New Guinea. He kept his distance from them, placing sentries to keep the infected away, while leaving the residents to their own devices, realizing that they would survive best if he left them alone.

He'd thought North America barren of intelligent human life, until, six months after he'd disregarded the entire continent, one of his sentries, investigating some odd signals in a little town in Canada got run over by a woman joyriding around in a Lamborghini.

tbc