'Immortality was never meant for me, darling. I'm human, I'm mortal, Loki, and I don't want to keep on living when everything around me corrupts and dies. The beauty of life lays in its fragility, my love. Besides, I really want to see if all that 'Heaven and Hell' talk we believe in around here is real or not.'

Those were the words Tony told Loki when he offered him the Golden Apple. Loki had begged him to reconsider, because for Loki a world without Tony was not a world worth living in (not anymore) but Tony didn't budge. Loki had been silent for days, not believing in what the Midgardians call 'heaven.' He knew that, because Tony wasn't Æsir, Vahalla wouldn't take him and neither would Nilfheim. He actually didn't know where humans went when they died. Everyone always assumed they just went away, not important enough to play a role in Ragnarök.

It used to leave him cold, that knowledge. Now it broke his heart, because it meant that one day, his lover would leave him. Forever.

His happiness.

His sanity.

His everything.

He had known, in the back of his mind, that goodbye would be unavoidable (unless he took the apple, why didn't he take the apple). But he had hoped. And now the only thing he could do was enjoy the time he had left with Tony. His Tony.

(please, please, eat the damn apple)

When he was with Tony Loki was happy. Tony kept the abyss away. The madness, the darkness: When he was with Tony he forgot it all. The human inventor had become Loki's light. Not to say that Tony didn't have his own demons, but Loki always tried to ease them as much as someone like him could. The two of them were once called broken, but in each other they found their fit. And that was enough.

Loki had not known peace like this since he was a child, thousands and thousands of years ago, sitting in the garden and smiling to his mother. He had not known love like this since… never.

Sometimes it felt like his heart was bursting out of his chest, like it all became too much, but then Tony was there and held him and Loki knew everything would be okay. He would never have shown that weakness to Tony if it was not for the fact that the inventor was the one in his arms just as often.

They bickered and laughed and lied and made love and they were one.

Loki's sanity, once almost broken, after the horse and the poison and his children and the heavy eyes aimed at his back and the whispered 'ragnarök' as he walked by and the mistrust and the betrayal and the 'no, Loki' – just as Loki was sure he could not take it anymore – Tony had appeared and glued his mind together through soft touches and acceptance and silent secrets shared on cold nights.

(so many things would be different if you would just eat-)

It had been a long time ago that Loki disliked the cold.

Sometimes, he wondered, what would happen to him if the glue that kept his mind together, that softened his pain and hid his demons, would disappear. He could not help but imagine the pale eyes of the oracle and the 'the trickster will bring the end of all'.

If you believe in a lie long enough, it will become true.

He did not wonder any further. Instead, he let himself be distracted by the little robot in Tony's workshop offering him a piece of scrap metal like a cat offering its master a dead mouse.

He stopped wondering at all.

And every day Tony's hair got a little bit greyer, his movements a little slower, but his mind stayed as bright as ever and his wit as sharp as ice.

(take it, eat it, why don't you-)

He kept fighting, of course, never putting the suit away. He was Iron Man and Iron Man was him. Loki didn't even try to talk Tony out of it: he knew that Iron Man and Tony Stark were the same. Only a fool would try to talk Tony out of being Iron Man. Loki was no fool. It was like Loki's magic, and to lose it was to lose a limb. He would never want to do that to Tony.

(just eat the fucking apple)

They had tried, of course, Steve and Pepper and Rhodey. But the inventor never listened. When they were alone he confessed that the fact that they tried to stop him being Iron Man hurt him, cut open old wounds he had forgotten even existed. And Loki just held him and assured him he was doing the right thing.

(I'll force it down your throat if I have to-)

When the faithful day arrived, with grey clouds, rain and the sounds of battle, another army and another war, over 25 years after they shared their first kiss, Loki closed his lover's eyes and kissed his lips one last time.

Tony's last words still echoed in his mind.

'K-keep on living, my love. Be h-h-happy. And please… do- don't forget me.'

Loki felt a tear dripping down his cheek and closed his eyes. He smiled, because Tony needn't have asked. No matter what, he would never forget.

He gently curled his hand around the arc reactor and removed it. He would keep his lovers greatest invention safe. The blue light was glowing strong and bright. Loki, in a fit of sentimentality or childishness or maybe it was just affection, vowed to never let it go.

From that day on, Loki always wore the arc reactor around his neck, the core resting right above his heart.

Because it was the only thing left of his heart.

They held two funerals for him. One was for Tony Stark, Iron Man, a worldwide event with the whole of America dressed in red and gold. There were shows and screens and many, many tears from people who did and did not know Tony and there was even more alcohol. Just as Tony Stark would have liked it.

The second one was quiet. It was for Tony, the brilliant mind who placed his friends and the safety of his world above all else. It was short. Secret. A small gathering, people holding hands and dressed in black and biting their lips and blinking their tears away. Pepper leaning on Steve, Bruce for once perfectly in sync with his inner monster. Others, standing tall and bowing their heads in respect. Loki, standing alone, even as the others left, green eyes changing to red as he knelt by his lovers grave in the cold and the rain.

The sky wept that day, not for the death of one man, but for the now sealed fate of all.

Hours later, Loki rose, and left his grief at his lovers' grave, together with the last pure and good pieces of his heart.

And he lived on.

Loki became a semi-permanent Avenger. He wasn't exactly on the team, but no one was ever surprised when he showed up in their tower or in the midst of battle. (Loki would always cherish the first few times he showed up in Avengers tower. The hole Clint's arrow made next to where his left ear once was, was still visible.)

He didn't change that much. He still lied and, still caused chaos or mischief but he helped the Avengers fight the battles they could not fight on their own. Every time he slept his hands and heart were curled around the arc reactor, the blue light the only thing keeping him sane.

His mind was still whole, barely, the blue light of the reactor mending and soothing on long, cold nights.

He dreamed of brown eyes and a soft laugh, of loving words and tender kisses, of broken promises and a terrible longing.

(if only he had accepted the apple)

Of course, fate was toying with him the day it happened. No solitary surprise, no private breakdown, no sir, that was not meant for him. They called him the trickster, they called him chaos, and apparently fate agreed.

Over the years the bond between Asgard and Midgard had only grown stronger, through both feats and battles. Thor and Jane, Jane her skin now smooth as a mortal's could never be, had become King and Queen of Asgard. Loki may or may have not interfered in Jane's test.

The Allfather and his wife supported them more often than not, but Thor was doing better than Loki had ever expected. He only had to save Asgard from its doom twice since Thor became king (and one of those times was his own fault, although he had gotten such a good laugh out of it). Thor's life as an Avenger had humbled him, and Asgard now flourished under his leadership.

The evening was young as the core groups of both Asgard and Midgard had come together to celebrate their long years of friendship. Old and new friends and allies alike shared food, drink and stories with a smile on their face. Even he himself could not help to sit there contently, even though he had technically not been invited, Loki always tended to ignore such trivial matters.

This was, of course, the perfect time for Loki's sanity to shatter.

The Avengers had changed over the years, of course. Only Thor, – who only helped when really needed, seeing he was also King now – Steve and Bruce were still alive. And even Bruce sought solitariness more and more, though he had gained control over the beast. Loki knew he wasn't the only one who missed Tony, and that the beast within Banner also missed his only friend.

Natasha had died trying to save a family of civilians, her age slowing her reflexes. After her death, Clint began taking more and more risks and in the end, gave up his life for North-Manhattan.

Loki never thought about the day Tony died. He couldn't.

The new SHIELD leader and the Allfather where discussing political matters. Jane and one of the new female Avengers – Wasp, if he was not mistaken - were gossiping and Volstagg was eating as much pie as ever. Loki listened with half an ear to all the conversations and stared at his food.

The reactor's light had begun to weaken in the last few weeks.

Loki's sanity did not fare well with this new development.

He had always found the energy of the reactor calming, and his mind and magic were always subconsciously wrapped around it. Therefore, the weakening of the light has not passed by him unnoticed, and he could not help but start wondering again, about the pain and the hate and the prophecy and-

(Tony, his Tony, who didn't take-)

Loki shook his head, determined not to think about it and enjoy the food and companionship. Once again, he tried not to think about the fading blue light.

But even though he was not focused on it, even though he let himself be distracted, he still felt it the moment it happened.

It was like the only source of light and warmth in a vast, barren wasteland had suddenly disappeared.

He felt cold.

The cold was not unfamiliar to him.

It was the cold of the void, the shiver of insanity he could never banish, the source of hate so fierce Loki felt it almost couldn't be his own.

But he wasn't sure. Not anymore.

The cold had been gone for so long. Once, Loki had been afraid of it, had resisted it, aided by the warmth of Tony's love until he felt immune to it and banished it to the very depths of his mind.

Now, he welcomed it as if it were an old friend.

(maybe it became one when he did not take-)

Sif had just made a jest at him and he had opened his mouth to reply when it happens. Loki froze.

Most of the others, who had been following their banter, looked at him expecting the comeback he would never give.

Loki's hand slowly crept up and touched Tony's reactor. He closed his eyes.

The core had died. The blue glow had vanished, the core becoming a flat grey colour.

Thor, of course it was Thor, it always had to be Thor, was the first to notice.

'Brother-'

Loki opened his eyes and silenced him with a look.

His mind felt cold. His emotions, drained, stolen, gone. His memories, locked away, faded away, stolen away. The last piece of love that had kept the darkness away had vanished – and the darkness had only been biding its time.

Many lifetimes ago, Loki had convinced himself that there was no such thing as fate.

Tony agreed.

The darkness disagreed.

Over the last few years Loki had found himself bored, lonely, cold. There was no one left to talk with, no one who could keep up with him and challenge him as Tony did. Loki wanted to lash out, to hurt all those who thought themselves dear to him, but he could not do it. He had promised Tony to behave, and so far he had kept his promise.

Now that the last piece of his lover was gone, so was Loki's restraint.

They say fate works in mysterious ways.

No one ever said that those ways were good.

'It has begun.' He half-whispered in Thor's direction, who put his hands on the table and looked his (not) brother in the eyes, worried.

Loki cleared his throat and tried to remember that he liked these people and that he did not want to see them suffer. He didn't succeed. The cold was consuming him, confusing him, leaving only pain behind.

'Consider this my last act of humanity. This warning. Be prepared.'

Also, the fact that he hadn't killed most of them in those few precious moments of confusion. It had been a long time since he had used his power to the full extent. People often forgot that though he may be on the side of the angels, he wasn't one of them. Loki, of course, never bothered to correct them.

'Loki.' The Allfather's voice was heavy, pretending to comfort him. All that knowledge and wisdom, and all Odin could ever say to his second son was his name. As if Odin would ever understand him.

As if he ever tried.

Loki just shook his head, and reached under his clothes to show them the arc reactor, now cold and grey.

The only sound he registered was Bruce chocking on a sob, sounding surprised even by his own show of emotion.

Loki would once have stayed to banter, to sow insecurity and chaos with just a few words, but he knew it would not help. As he looked around the table and saw that Sif had already drawn her sword, on guard, he just sighed.

Despite everything, Asgard did still not wholly trust Loki. They never would, not when the myths and legends declared him evil. Not when his roots lay in Jötunheimr and his children were deemed monstrous by birth.

Loki disappeared.

There was only one path open to him now.

(so many were closed when he didn't take-)

The seeds of his plans had been sown for many centuries. Some seeds were sown by purpose, as they were useful. Others by accident. And some he had sown as if in a cold, cold dream, acting but not thinking as if led by an unseen force.

It did not matter. All was prepared for the end of the world.

Loki freed his children, his happiness at seeing them overcome by the coldness he was feeling. He opened the stone doors to Svartálfaheimr, the groans of the dwarves rising up from behind them, and insulted them until they hot with rage and ready for war. He freed Surtr and let the fire jötnar of Muspelheim loose. He opened the gates to Asgard for everyone and everything and heard Heimdall blow the Gjallarhorn, alarming Asgard.

Not long after that the doors to Valhalla opened.

The only thing he remembers after that is war. Destruction. Blood, screaming, fighting, dying, cold.

The Allfather's head being bitten of by Fernir, his son roaring victoriously. Víðarr tearing Fernir apart, taking revenge. Blood on his clothes, after slaying Sif had been more troublesome than he had originally thought. Thor and Jörmungandr fighting a long battle, Loki watching paralyzed from the side-lines. Thor slaying his son, but collapsing from poison soon after. Loki not being sure if he should be happy or not, if it was wrong that he was not feeling anything at all.

(he kept remembering that day, Tony's face. Loki had always saved an apple for him in case he changed his mind, although in his heart he knew that would never happen)

Freyr and Surtr battling, blood all over them both. By this point everyone and everything was drenched in blood. Even the Hulk had been silenced, collapsed after being hit too many times. The invincible super-soldier not being so invincible after all, his once blue suit now bright red. Loki's own daughter being the one to rip Rodger's head off in the end while laughing manically. SHIELD and its agents being slaughtered like sheep.

The once golden city turning blood red, crumbling down on itself.

Asgard had fallen.

Loki watched it all with empty eyes, his heart and soul long gone. The only thing left for him to do is fulfil his fate.

In his right hand, his poisoned dagger.

In his left hand, the arc reactor.

Loki received blow after blow, fighting harder than usual due to his inability to use his left hand, killing creature after creature not caring whether he is supposed to be at their side or not.

In Ragnarök, there are no sides. Only death and destruction.

He faces Heimdall. Their battle is long and heavy. He fires the last blow he knows will be fatal while Heimdall pushes his staff through what's left of his heart. He sees and answers the sad gaze Heimdall wears before collapsing.

The cold is finally starting to fade away.

The last thing he sees is his reactor, Tony's reactor, still clutched in his hand.

Until the end.

He thinks he hears the faint echo of familiar laughter, thinks he sees the brightest flash of red and gold, thinks he feels a soft and warm hand caressing his cheek.

He thinks he hears the only voice he ever wants to hear.

'I missed you, my love. Welcome home.'

But he is not sure.

Maybe there is some kind of 'heaven' for him, after all.

I'd listen to the words he'd say
But in his voice I heard decay
The plastic face forced to portray
All the insides left cold and grey

There is a place that still remains
It eats the fear it eats the pain
The sweetest price he'll have to pay
The day the whole world went away

A/N: I read the headcannon on tumblr and I just had to make this. Read it over and over and kept changing it but in the end just decided to post it. Played with some facts: Jane didn't have to take the courage test, and I'm sure the original order of the battles of Ragnarök is different, but hey, this fitted. I don't own anything in here, not even the whole plot, haha. I'm sure there's also a Sherlock quote somewhere in there.

The original Norse Mythology says that "In Valhalla, the dead join the masses of those who have died in combat known as Einherjar, as well as various legendary Germanic heroes and kings, as they prepare to aid Odin during the events of Ragnarök." So I applied that concept. There are no precise details to be found on how Ragnarök happens but I am sure this is a possibility.

I did try to keep to the Norse Mythology as much as possible: although I do think that there is, because Ragnarök is not only an end but also a beginning, no afterlife for the Gods after Ragnarök but I wanted some kind of sweet end.

My Tumblr is king-of-sass, for those interested. The song at the beginning is; 'The Day The World Went Away' from Nine Inch Nails. I hope you enjoyed this.

Thank you for reading!