This is based of parts of the Doctor Who Episode, The Doctor's Wife, from series Six.
This takes place sometime during season two, at a HYDRA base. Triggers:panic attacks; paranoia and psychological torture.

They had gotten lost from the rest of the team, having wandered down an unknown corridor at what was presumed to be an abandoned HYDRA base.

Jemma shivered, the temperature having dropped by many degrees.

"You okay?" Fitz asked, smiling at her, hoping to reassure her, even though fear had started to creep in, working it's way through his mind. They were starting to repair their friendship and both of them couldn't be happier.

She nodded. "Just can't wait to leave here. I could've sworn that the team..."

"Where right behind us."

She nodded again, looking over her shoulder. Something felt wrong. Very wrong. Something was there. Or someone. She wanted to try and shake that feeling, but she couldn't.

She hadn't realised that she had stopped in the middle of the corridor, looking behind her. The lights were now flickering, casting shadows.

Her breathing was heavy, and she couldn't seem to settle it. Something was very off about this whole place. And all she wanted to do was leave.

"Fitz," she whispered, not wanting to draw attention to them, from whatever was lurking in the shadows. "Fitz."

No reply. She spun around, in a desperate bid to find him. But he wasn't there. He was gone. Fear was now turning into full fledged horror. "Fitz?"

Still no reply, he wasn't there. But there was only one of three ways he could have gone.

Back the way they came, the way she was facing. But he couldn't have. She would have seen him.

The second way was that he was walking on, not knowing she had stopped. But that also wasn't possible. He would have hears her pleas for him.

The final way. Down the dark side corridor where the lights were all but off. She took a shuddering breath. She should've brought a torch with her, but she hadn't brought one with her personally. Fitz was carrying everything that they needed for the mission.

She closed her eyes and counted to ten in an attempt to steady her breathing, but it didn't work. She set off down the corridor anyway. She had to find Fitz. Find Fitz then the rest of the team.

The flickering lights cast an eerie glow on her face, caused shadows to dance on the walls and light up...

"Fitz!"

He was sitting against the wall, knees drawn up, head down. When he looked up, he was furious. "You left me! Again!" he sapt, rising to his feet.

She stumbled backwards, saying that it wasn't her fault. That she had simply stopped to look at something. That there was only mild confusion.

He shook his head. "You don't get it, do you? I've been waiting here for hours!"

She shook her head. She couldn't have been standing staring at the corridor for hours, could she?

He laughed, a wicked, cruel laugh. "You've did it again. Abandoned me."

She was crying now, tears streaming down her face. She opened her eyes, and he was no longer there.

She collapsed to the ground as she tried to comprehend what was happening, and what to do next. She had to get out of there. She had to find Coulson. He would know what to do.

She got to her find, swaying slightly as she found a headache starting to form. That's all she needed now.

She stumbled down the rest of the corridor, hoping to find Fitz there. And he was right. She had left him. Again. And she could have been standing there for hours. She didn't know. Everything was so disorienting.

Once she reached the end of the corridor, there were more ways to go, just corridors branching of corridors. A labyrinth She had no idea which way to go, which way Fitz would have went.

She turned back to head back the way she came, deciding that tracing her footsteps would be the best approach but found that metal doors had closed. She hadn't heard them close, and realistically, something that heavy would have made a sound. But she mustn't have heard it.

Everything was confusing her now. Not hearing the doors close, Fitz implying that she had stood, staring down a corridor mindlessly for hours. She took a breath, trying to regain her composure. But she couldn't.

She had no idea where she was, where her team was, where Fitz was. And she wanted to find him, to apologise, to explain why she left him.

Oh God, he hated her. Hated her for everything she had done, everything that was wrong. It was her fault. It was all her fault. She had caused so much pain, so much hurt. Not just to him, but to everyone.

It was her fault Trip was dead.

It was her fault that Ward was still out there, causing pain.

She couldn't help Skye.

She couldn't help Fitz.

She couldn't help anyone.

She should have went home. To her parents' house. Stayed there and never left. She should have completely reinvented herself. Let this version of Jemma Simmons, the one that had caused everything to go wrong, die. Let her lie at the bottom of the ocean dead.

The ocean. She lifted her head. She should have left Fitz take the oxygen. Insisted that he should. But she didn't. She took it.

A sudden noise in one of the corridors to her left caught her attention and she decided to investigate, a stupid, dangerous, reckless, foolish plan, but one she did nonetheless.

"Hello?" she asked nervously, hoping it was one of her team. It had to be, it had to be, it had to be. They were the only ones there. Weren't they? Or were there others? More agents, both S.H.I.E.L.D. and HYDRA, that she didn't know about? And now she was heading into a trap, unarmed, defenceless.

"Jemma?" a voice called out. Fitz, but only it wasn't Fitz. It sounded like him, but only it didn't. He sounded older, and in pain.

There was a noise like someone standing up, and she was right. It was him. But older. "Fitz?" she sobbed, tears streaming down her face, clinging to her eyelashes.

"You let me again. You promised you wouldn't but you did!"

Did she promise that, did she really promise that? She didn't know. Everything was confusing her, and only adding to her headache.

"I waited here for you! You said you'd come back!"

She shook her head, not wanting to believe that he had aged without her. That she was still youthful and he wasn't. That she had left him by himself, while she spent years wandering around the corridors of the HYDRA lab, not bothering, not even attempting in all those years to find him.

"I..." she tried, not able to finish her sentence, stumbling back as he shouted at her.

Shouted that he had wasted his life, waiting for her. That he could have been happy, could have had a family. But no. He wasn't it all, waiting on a girl who made promises and broke them. Shouting of a life he could have had but he didn't.

Because of her. It all came back to her.

There was a number of metres in between them, she had the advantage of her youth, and having been on her feet originally. She continued walking back, sobbing and apologising. He wasn't listening to her, and why should she? She had ruined his life, in more ways than one.

She fell backwards, but he stopped as another metal door slammed shut in front of her. Her breathing was heavy, laboured. She couldn't get a breath in. She was going to die here. Alone. And Fitz hated her. And now she was alone. And now she was going to die down here. Alone.

She spun herself around, resting her back against the metal door, the coolness of the metal providing her with some reassurance. But not enough.

She looked down the corridor. It was dark, the lights not having yet flickered on. And as she stood up, they did. Each one turning on individually, down the whole corridor. And what she saw written on the walls made her stumble back, and not for the first time that day.

Hate Jemma.

Die Jemma.

Kill Jemma.

And it was written in blood. But whose blood? She didn't know (did she really want to know?)

She tried to make her way down the corridor, trying to ignore the messages on the wall that were directed at her.

Something caught her eyes.

"No!" she screamed again and again. Trying to deny what was in front of her. It couldn't be.

He couldn't be.

There were arms around her waist suddenly, restraining her. Holding her in place. She screamed louder and kicked harder, trying to get them off her. Trying to make them release their hold on her.

The voice told her to calm down. That it was going to be Okay. She recognised that voice. At least she thought she did. She thought it to be May. But she had to be dead, if...

That was the last thing that had crossed her mind before the darkness took over.

She woke up surrounded by white, with an IV drip in her hand. She went to rip it out when a voice told her no.

"Jemma, you're fine. You're back on base. We found you."

She shook her head, not wanting to believe it. "You..." she whispered.

He nodded, and took her hand in his and rubbed his thumb gently over the back of it. "You're ok Jemma."

"What happened?" She had no idea, except of the horrors she had been subjected to, horrors that felt so real, that were so real.

Fitz sighed. "There was hallucinogens in the air, down the corridors we went. We got separated. May found you, screaming and crying at a blank wall and gave you a sedative. Except it wasn't a blank wall, was it?"

She shook her head, and explained everything she had seen, and watched his face fall. She could tell that he blamed himself, but it wasn't his fault. it was hers.

"But I need to tell you why I left. Please!"

He nodded, knowing that it was now time talk about what had happened between the two of them, and what would happen in the future. He was glad that they were friends again, even if what had just happened (or what she thought had happened) maybe complicated things.

And what she said, he never expected. He thought she had left as she couldn't accept the change, that she didn't reciprocate the feelings.

He didn't know that she had left to help him, that she had left as she thought that she was making him suffer, making him worse. That she only finished his sentences to show that no matter what, she would love him. No matter what, they were, and always would be, Fitzsimmons.

He gently cupped her face in his hand, using his thumb to now gently stroke her cheek. "Jemma Simmons, in no universe could you make me worse, could make me suffer."

She nodded, though her eyes filled with tears. "I'm sorry."

He shook his head. She didn't need to. They had simply misunderstood each other and now that it was clear, they could put this behind them.

"Jems, you mean so much to mean. I'm sorry to. For everything."

She shook her head this time. "It's all my fault."

"No. Don't you ever think that, you hear me. Don't you ever blame yourself for what has happened. It's not your fault. And it could never be your fault."

She nodded as the tears finally started to make their way down her face.

Looking at her like this brought back the memories of what he saw, of how he saw her dead, or dying, or tortured. And how he was powerless to help. How he had to watch this happen again. And again. And again. And not be able to do anything. Coulson had found him and managed to talk some sense into him. It wasn't until he was in the fresh air that everything became clear.

He thought she had fallen asleep again when she asked, "What did you see?"

He swallowed, knowing he should tell. "You. Hurt. Dead. Again and again and again. And I was powerless to help."

She lifted her hand and placed it on top of his, which was still resting on her face, proving some warmth and comfort. "You saved me."

He gave her a smile as tears started to make their way down his face.

They were silent for a long time before she smiled at him, her eyes lighting up for the first time since she was awake. They were excited and full of joy. The way they should be. Not full of fear and sadness like they were so often these days.

"What?" he asked.

She gave him a knowing a smile, as if to say that he should know what she was about to say.

"I love you."

He didn't know how to reply to her. He still loved her, but she had never said it back to him. But she also never said that she didn't love him.

"And I've loved for so many years but I didn't think that you loved me," she was babbling now and he couldn't help but smile slightly more at this. "And I never got to say it to you. And I didn't want to say it in case you didn't love me back and when you did I didn't have the time to say it back and I know you probably couldn't love me now..."

He cut her off. "Jems, nothing could ever stop me from loving you."

And their lips met.

This is one of my fave Doctor Who eps, and there are so many similarities between Amy and Rory/FitzSimmons. Hope you enjoyed!