Warning: Blood and gore

Spoilers for: The Time of the Doctor

Disclaimer: Don't own Thor or Doctor Who

Chapter 1 – Tonight

"That was wonderful, sweetie."

River leaned over to give the Doctor a peck on the lips.

She sat back and pulled a compact mirror from her pocket.

"I'm glad. But there's still one more thing I have planned to show you."

River snapped the mirror shut and turned to face the Doctor. "More?"

The Doctor nodded.

River grinned. "Sounds exciting. Where are we going?"

The Doctor said nothing, but his eyes were filled with mischief. "You'll see."

The Doctor pulled their picnic basket round so that they could pack everything away and politely pretended to be completely focused on the plates he was stacking while River gorged herself on the last few strawberries.

Once everything had been put away, the Doctor stood and pulled River up beside him. She rested her hand in the crook of the Doctor's elbow, and he begun on the way down from the green hills and into the city.

The town was immensely busy, with people bustling around wherever they looked. River's eye would occasionally catch something and she would send an enquiring look the Doctor's way, but he merely smirked and continued on. When it became more obvious that they were headed towards the huge golden citadel in the centre of the city, River spoke up.

"Doctor…"

The Doctor kept his face turned from her, and his gaze fixed on the structure before them.

It only took a few flashes of the psychic paper to get them into the palace and down to the lower levels.

With each staircase they descended, River's suspicion grew.

"Where are we going?"

The Doctor gave her a small smile. "To see an old friend."

A few moments later, they reached the lowest level of the citadel. They emerged at the end of a wide corridor lit by artificial light with cells on either side: large rooms cut off from the rest by grids of crackling golden light. Some had several prisoners inside, others only one. All of the poor incarcerated looked considerably worse for wear; some were even sporting black eyes or other minor injuries.

Each had a guard stationed outside.

Each except one.

Halfway into the dungeons was an empty cell guarded by a woman in full armour. As soon as she saw River and the Doctor approach the cell she was guarding, she drew her sword and assumed a defensive position.

"Who are you?"

"I'm the Doctor, and this is River Song. And you must be Sif! Wasn't expecting to see you here, today. What a surprise!" The Doctor grinned.

The woman's eyes narrowed and the blade inched a little further to the Doctor's torso. "How do you know my name?"

The Doctor waved his hand. "That doesn't really matter right now. What matters, is where he?" He pointed to the cell.

Sif grit her teeth. "I don't see why that's any of your business."

The Doctor's eyes darkened.

"It's my business because I know that that man is a dangerous criminal, and you will need all the help you can get to find him before he does any damage. And I've met him outside of Asgard, so you could say I know a little more about his cosmic hiding places than you do."

Sif straightened, though she kept her sword pointed at the Doctor. "You know the Silvertongue."

The Doctor smiled sadly. "I'm sure he would be thrilled to hear you call him that."

Sif sneered. "I don't care if he's thrilled or repulsed; I'll call him what I like after what he's done."

"So you think he's alive?"

Sif snorted. "You think he's not?"

The Doctor shrugged. "How can I think anything either way when I don't know where he is? I was under the impression that he would be in this cell. That is why we're here, after all."

He gestured to himself and River.

"If you didn't know that he isn't here, then why should I enlighten you as to his whereabouts?"

"So you do know his whereabouts?"

"And you don't. Therefore, I believe, I have the upper hand."

The Doctor took a moment to reassess his strategy. He looked down at Sif's sword, still pointed at his chest. Quickly forming an idea, he straightened himself to his full height and assumed his most military pose.

"Lady Sif, you may have heard of me: I am the Oncoming Storm, the Predator of the Daleks, the Great Exterminator. I have fought long and hard to make this universe a safe place for all to live in, and we both know that Loki threatens that. Let me help you put an end to his dangerous exploits."

Sif stared at him, her eyes narrowed. "The Oncoming Storm? I have never heard of such a warrior. I pray, continue on your way. This is getting tiresome, and I would hate to actually have to run you through."

The Doctor sighed and turned to River.

"Darling, do you have your Vortex Manipulator?"

River smirked, already reaching for the black strap around her wrist. "Well ahead of you, sweetie."

There was a flash of blue light, though River was still by the Doctor's side when it faded.

Before them, Sif groaned and raised her free hand to her head.

"You…" she breathed, staring up at River with something like childlike wonder in her eyes. "You were… when I was a child… But… that never happened… But it did…"

Sif gasped; her eyes widened. "But… that means… I…" She turned to the Doctor with fear in her eyes. "Thor took Loki to Svartalfheim to give the Aether back to Malekith. They are yet to return."

The Doctor nodded. "Thank you."

~{Loki-and-the-Doctor}~

"So… Norse god of mischief and lies. You know me so well."

River leaned against the Doctor's back, resting her chin on her shoulder and trailing her hands down his arms while he fiddled with the TARDIS controls.

"Well, that was the idea," he mumbled.

"What's wrong?" River frowned. She stepped back. The Doctor moved around the control panel, flicking switches and pressing buttons. "Doctor?"

"Something doesn't feel right. He should have been in his cell. There must be something going on, especially if Thor is talking to Loki after what he did."

"What did he do?"

The Doctor waved it away. "It was a whole… New York thing."

River bit her lip. "Oh."

The Doctor leaned against the console and looked up at River. "Different New York thing."

"Obviously."

The Doctor pushed himself up from the panel. "Let's just say we have a shared hatred of that particular city. Shame, really. I had such a good time in the New New one…"

He trailed off and continued with his in-flight checks.

River regarded her husband. "You're worried."

"Well, he is the god of mischief and lies. Who knows what sort of trouble he's got himself into this time?"

River smirked. "Sounds like it'll be an adventure. And no offence, sweetie, but that's just what that picnic, lovely as it was, was lacking."

The Doctor said nothing as the TARDIS landed. He strode over to the door and wrenched it open. River sighed and followed him, stepping out after him into the bleak world beyond.

There was no life to be seen on this dark world: only dim light, black sand, and large rocks. The terrain made it tricky underfoot; while the Doctor strode onward with nary a worry, River was finding it so difficult to keep up in her heels. It didn't take long for the Doctor to be halfway across the dark landscape, while River was still only just out of the TARDIS.

"Loki!" the Doctor cried into the distance; he received no answer but the blowing of the wind. Dust was flying through the air and making it difficult to see ahead. "Thor!"

River was beginning to worry, as the Doctor showed no sign of stopping.

"Where is he? Where-"

River was too far behind the Doctor to see what had suddenly made him stop, but he was only stationary for a moment before he broke into a sprint. River did the same, as best she could. As she cleared a small crest, she noticed a green-clad figure lying on the ground. It wasn't moving.

"Doctor…"

The Doctor wasn't listening. He stopped next to the body and looked down at it, his hands curling into his hair.

He didn't move until River reached him. Then, he bent down, and – with hands shaking – reached two fingers forward to press into the figure's throat. His face fell.

"Doctor?"

The Doctor sat back on his haunches. "He's dead. Run through." He gestured to the red stain on Loki's middle.

River stood a few feet back from the Doctor, unable to see his face. He didn't move, and she didn't dare move closer.

A moment passed in which time didn't seem to have moved at all. Then, suddenly, he slammed his fist into the ground next to the body.

"No!"

River winced. "Doctor…"

"No, no, no, no!" He kept punching the ground until River was sure that he would break his skin – or his bones. "I still owe you! You can't die before I pay you back! I can't lose you as well! You are not done in this universe."

The Doctor reached forward and grabbed Loki's shoulders. He shook the body, and blood seeped from the wound in his abdomen, dripping down onto the ground below. The Doctor watched with both revulsion and fascination as it pooled next to Loki's form. His gaze drifted back up to the fatal wound…

River saw something click in the Doctor's brain. He stood abruptly, twisted on his heel, and made for the TARDIS.

"Doctor?" River called after him as he passing by her without a second thought, but once again she was ignored. She huffed, checking that the Vortex Manipulator was still on her wrist before going to stand next to Loki's body.

She looked down at his face, so pale and peaceful in death, his hair tucked neatly under his head like someone had been there to arrange it before him.

River decided in that moment that if she ever met Thor, she would make him pay for whatever part he had played in the demise of this man – this friend of her husband.

She was brought from her thoughts by the sound of shoes scuffing on the dust underfoot. The Doctor was making his way back over with a jar in his hand: a jar filled with what looked suspiciously like nanogenes.

"Doctor, what are you doing?"

The Doctor still ignored her, walking over to Loki and kneeling by his side.

"Do nanogenes know the biology of demigods?"

"These ones do," the Doctor explained as he twisted the jar lid open and encouraged the nanogenes towards Loki's wound. "We once had a run-in with a sword-wielding Weeping Angel, and I healed him with these. I've been hanging on to them ever since; knew they'd come in handy one day."

River watched, fascinated, as the nanogenes got to work. The glowing lights swarmed around the wound, making it impossible to see what they were doing to the trickster's flesh. When they were done, they formed themselves into an almost perfect sphere and floated up from Loki's abdomen. The Doctor coaxed them back into the jar and placed the lid back on.

For a moment, it seemed as though they were too late: the wound was indeed fixed, for the flesh was visible and unmarred through the tear in his clothes, yet Loki still lay there, motionless and pale.

The Doctor stared down at his face.

Suddenly, Loki took in a deep breath, and his eyes flew open.