Ten years after Thanos attacked the city, Tony finally completed work on his new home and moved out of his hotel penthouse suite.
"Well, this is a lot more humble than your last abode," Loki announced, as he appeared on Christmas Eve, leant against the living room doorway of Tony's new mansion. "Your name isn't up in lights, emblazoned across the sky for all to see."
"The days of announcing my home address to every villain, alien and terrorist are long gone," Tony replied as he stared into the open fireplace.
"I imagined something a lot more ostentatious," Loki said, and then he ran a finger over the wall. "Oak panelling? Really?"
"I was aiming for traditional," Tony replied, and then he turned to face Loki. "Actually it's a treated timber shell over a synthetic Adamantium structure. A little invention of mine that I haven't told SHIELD about yet."
Loki grinned and said, "That's more like the Stark I know."
"Plus, I didn't build up," Tony said as he tapped three times on the panel next to the fireplace, which moved to the side with a hiss to reveal an elevator door. "I built down."
"Down? You built a dungeon?" Loki asked.
"Not exactly," Tony said with a raised eyebrow. "There are three more levels down there. Fully independent oxygen, water and power generation systems and enough food to last for two years. A nuclear bomb could hit this place and whoever was in it would be safe."
"That hardly seems like the plan of a man content to drink himself to death," Loki stated.
Tony shrugged. "There's a fully stocked bar and a still down there too."
"And is it the only bar in the building?" Loki asked. "I assume it must be, since a gracious host, such as yourself, would have offered me a drink by now."
"Bar's in the corner. Knock yourself out," Tony replied as he closed the hatch that covered the elevator.
Loki unfolded his arms and moved towards the bar, where he investigated the bottles until he found one that met with his approval. He unscrewed the cap and filled a large tumbler almost to the brim with a sickly looking green alcohol.
He took a sip of his drink and then moved over to where Tony stood by the fireplace and asked, "What's this? Two stockings? Are you expecting company?"
Tony briefly glanced at Loki. Coughed slightly, and said, "Well, I kinda thou-"
"Oh I see," Loki interrupted as he ran his fingers over the green stocking that hung from the white marble lintel above the fireplace. "This one is for me?"
"Maybe… If you want it," Tony replied.
Loki smiled, one corner of his mouth quirking up into an almost sarcastic grin. "Such sentimentality, Stark, but a nice thought. Thank you, but I fear I have been a naughty boy this year and my stocking will remain empty."
"Been up to your old tricks?"
"I may have inadvertently started a war," Loki replied, grinning so much he could barely take a drink from his glass.
"A war?" Tony asked.
"In my defence it was only a small war and one must amuse ones self when boredom strikes," Loki replied.
Tony turned back towards the fire and laughed.
At some point during the night, after he had finished a bottle of Absinthe, a bottle of champagne and two bottles of Vodka, Loki flopped to the floor and announced he was sleeping in front of the fire and shouldn't be disturbed until at least spring.
"Do you need a bucket?" Tony asked. "I don't want you throwing up that green shit you were drinking on my new carpets."
"Just leave me be," Loki slurred, as he waved his arm pathetically at Tony and curled into a ball on his side.
Tony grabbed his arm as it waved in the air and pulled. "Get up. You are not sleeping on my floor."
"No, Thorrrrr," Loki whined. "Let me sleep."
Tony lowered Loki's arm back to his side and closed his eyes, trying to steady his emotions for a minute, and then he knelt on the floor.
"Loki," he said, gently patting him on the cheek. "Come on, get up. You'll be more comfortable in a bed."
Loki suddenly sat up, and looked around himself. "Where did Thor go?"
"Thor's gone, Loki," Tony sighed. "You remember, right?"
Loki's face crumpled slightly. "Forgive me. I know not what I say."
"It's OK," Tony replied. "That's kinda the aim of drinking. The forgetting part. I just don't seem to be able to manage it lately."
It was Christmas eve, and Tony was 65 when he flopped back into the snow in the garden outside his mansion and asked Loki if he had ever made a snow angel.
"What are you doing?" Loki asked, almost dropping the bottle of Whiskey he held in his gloved hand. "You'll freeze."
"Come on, get down here," Tony shouted as he waved his arms and legs in the snow. "You're a Frost Giant. A bit of snow won't bother you."
"As I have told you repeatedly I'm not a Frost Giant in this form. My tolerance for the cold is the same as any Asgardian."
"Come onnnnnn," Tony whined.
"Oh all right," Loki said, as he placed the bottle securely in a snow drift between them and flopped down beside Tony. "Should I end up laying in something disgusting, you're paying to have my suit cleaned, Stark."
"Fair enough," Tony replied. "OK, so what you do is you flap your arms and legs like this, and voilà, snow angel."
Loki copied Tony's movements, and then said, "I feel quite ridiculous, and not particularly angelic."
"You can't really see the effect till you get up, and to be honest I don't feel much like getting up," Tony said.
They lay in silence for a moment, gazing up at the snow clouds, tinted orange by the glow of the city lights, and then Loki asked, "Do you think Christmas carols are disturbing?"
Tony propped himself up on one elbow, reached for the Whiskey bottle, and said, "What?"
"He sees you when you're sleeping. He knows when you're awake," Loki sang. "Does that not sound a little alarming?"
"Are you calling Santa a stalker?" Tony asked.
"He knows if you've been bad or good. So be good for goodness sake," Loki sang again. "That part sounds like a threat."
"Santa leaves you coal in your stocking if you've been bad."
"And perhaps the coal is meant to serve as a warning. If you are bad Santa might burn your house down next year."
Tony let out a laugh, then raised the bottle to his mouth, and downed a few gulps.
"If Santa can see everything, then perhaps he is actually Heimdall?" Loki said, and then he added, "Oh wait Heimdall is dead. Does that mean Santa is dead?"
"I think you need more booze," Tony said, handing Loki the bottle. "Come on, let's get up and observe our host of angels before my ass freezes."
They climbed to their feet, taking care not to disturb the snowy outlines, and Loki said, "They don't look very much like angels."
"Are you kidding me? They look so much like angels!" Tony said, and then he sang, "Hark! The snoowww angels sing, Glory to the Asgardian king!"
Loki let out a snorting laugh, and continued, "Peace on Midgard and mercy mild. A god and a sinner reconciled."
Tony laughed, and sighed thoughtfully. "Are we? Reconciled, I mean?"
"I like to think so," Loki replied quietly. "Come on. Let us get you inside, old man."
"Hey, less of the old!" Tony said cheerfully, as he started up the garden path, back towards the mansion, and then he put his arms in the air, and sang loudly, "Joyful all ye nations rise! Join the triumph of the skies!"
The 15th year after attack the on New York was a bad one for Tony. He made the mistake of commissioning a memorial to all those who died on that day, and had it built upon the vacant land where the Avengers Tower used to stand.
He thought it would be a shining beacon of hope that would inspire everyone across the city, but as he looked at it from his bedroom window, all it did was mark out the spot on the horizon where he lost everything and everyone he ever cared about.
Tony did not attend the dedication ceremony. He spent it passed out in the underground levels of his mansion, and when he woke he altered JARVIS's protocols, and began work on a new project.
When Loki arrived on Christmas Eve it seemed he was faring no better than Tony was, as he laid on the rug in front of the blazing fire, with a faint green glow round his fingertips as he flipped through playlist on Tony's music system and finally settled on a haunting Ludovico Einaudi piece.
"This isn't your usual festive cheer," Tony said, as he watched Loki close his eyes.
"Forgive me if I am not feeling all together cheery," he replied.
"You could say that," Loki replied, with his eyes still shut.
"So what exactly do you do all year?" Tony asked. "Go out and cause mischief all over the place?"
"I rule Asgard."
Tony was puzzled, and asked, "But… they're all dead, right?"
"I do not need subjects to be a king," Loki replied. "I only require a kingdom."
"So you spend all year in Asgard, alone?" Tony gasped.
"Not all year," Loki replied. "I visit you."
"I won't be here forever, Loki," Tony said quietly.
"I know," Loki said so softly it was barely a whisper.
"So what will you do?" Tony asked. "When I'm gone?"
"I am not sure," Loki replied. "Perhaps I shall go travelling to the outer reaches and find Thanos."
"You know he would kill you."
"And that would entirely be the point," Loki sighed. "Perhaps he would finally be able to give me the death I ache for."
Tony knew he should say something, try to talk him out of it, but he couldn't bring himself to do it. He felt the same way.
"Your myths foretold a death for Thor at the hands of the serpent, but I always thought that one day we would kill each other after years of pointless battle," Loki said. "I never thought for a second that it would end like this, with him going first."
"It's late," Tony said. "You're just tired."
"Aye, I am. I am tired of death and misery and being utterly alone."
"You could come see me more often," Tony said.
"Stark, you said yourself you do not have much time left and I will be forced to watch you die, slowly, in front of my eyes and then I will be left alone again. I cannot take it any longer."
"I know how you feel," Tony said, closing his eyes.
"At least you have the option of death," Loki said. "Even if you couldn't do it yourself, all you need do is wait, and eventually it will catch up with you. If I die with a knife in my hand in battle at least I would get to see Thor once more in Valhalla, but it seems that I am condemned to simply fade away into nothingness."
Tony stood quietly for a moment, and then said, "I made myself a new suit recently. Gave it a new self destruct system, but it has this tiny little flaw in it."
Loki opened his eyes and gave Tony a confused look. "And that is?"
"JARVIS, bring up the schematics for the Mark 49," Tony said.
"As you wish, sir," JARVIS replied tersely.
A glowing hologram appeared in the air showing outlines of the new armour Tony had designed and he flicked through the pages until he found the diagram he wanted and then drew his hands apart, expanding the image.
"See this fold in the metal here?" Tony asked, as he pointed out a line in the front of the suit, just below the arc reactor. Loki nodded. "Heaven forbid that anyone ever finds out about it, but one well placed blow here, and its game over for me and anyone stood within 6 feet of me."
"Game over?" Loki asked.
"Lights out, as in completely obliterated," Tony replied. "Thor once told me about the Dark Elf weaponry and that mini black hole thing sounded kinda neat, so I made my own." Tony shrugged, and continued, "Shame its so unstable that someone could set if off with just a knife."
"I see," Loki replied as he rubbed his chin.
"Great suit though isn't?" Tony asked, as he shuffled through the holograms again and brought up the coloured external design. "Really distinctive colouring, with just the plain red. You couldn't mistake it for one of the other ones."
"But you are an Avenger no longer?" Loki asked. "What reason would you have for wearing your suit once more?"
"Maybe one day, eventually, an old enemy shows up, one that I was familiar with or had fought before, it would make sense for me to go up against them again," Tony said with a shrug. "Maybe that old enemy would get lucky and set off the self destruct."
"But surely your A.I. would prevent you from creating such a device?"
"JARVIS has a new set of protocols, which means he can't stop me doing anything I want, even if he thinks it's a bad idea."
Loki looked at the design closely, and quietly asked, "And you think it would work?"
"I'm certain it would work," Tony nodded.
It was a dreary, damp April day when Tony got a call from the new director of SHIELD saying that Loki was in Times Square destroying everything that moved.
"Tony, we need your help," he said. "You've been up against Loki before. If he has any weaknesses, we need to know them now."
It took Tony exactly 12 minutes to arrive at Times Square.
Awed by the unexpected presence of Iron Man, the new Avengers team moved back behind him as he walked forward.
Loki stood among the wreckage of smoking cars, and held his head up high. "Have you come to challenge me, Man of Iron?"
"I have," Tony replied, raising the faceplate of his helmet.
"You must have a death wish if you think you can defeat me, Stark," Loki said, a soft smile creeping across his face.
Tony smiled, and said, "It's time to end this, Loki."
A knife appeared in Loki's hand, and he said, "Aye, it is."
They surged towards each other. Loki grabbed Tony by the back of the neck, pulling him close, and whispered, "Thank you."
Tony wrapped one arm round Loki's back, then placed his hand over Loki's, wrapping it round the hilt of the knife, and together they drove it into the fold of the metal.
The reports that came into SHIELD varied in their details.
Some reported that Loki stabbed Tony in chest after they traded blows.
Some reported that it was Loki who had conjured the blinding whirlpool of light that had sucked them both in.
All the reports agreed on one thing: both Tony and Loki were smiling as they were obliterated by the black hole.
That year, on December the 24th, the NYPD choir stand and sing their songs around the tree, and for the first time in 16 years, no snow falls on Christmas Eve.