A/N: SPOILER ALERT FOR THE ANGELS TAKE MANHATTAN (AU; SuperWho; Sartha) based on the "what if" prompt on Tumblr; the prompt was "What if Sam got sent back in time by the angels and Martha had to say goodbye to Ten?"

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"Martha, come away. He's gone, Martha, he's gone…"

The Doctor's voice was a frantic urgency that barely broke through the haze in Martha's mind. Seconds ago, as she stood in the graveyard laughing and relieved to be safe again, she had watched Sam disappear before her eyes. Now, her gaze was fixed on the angel, the stone creature wearing a feral growl on it's cracked face, pointing accusingly at her.

They had escaped through a paradox, and this was an avenging angel, ready to make things right.

"Doctor, wait," Dean broke in, and she could hear the tension in his voice—she knew that he was pointing a gun at the angel, not caring how futile it was. There was a sort of wild calm in his voice, almost like denial. "We can go get him, can't we? Take the Tardis back…" His voice caught, because he knew the answer already.

It took the Doctor a moment—she could hear the grief in his silence. "No, I can't, I'm sorry, Dean." He reached out and gripped her shoulder, trying pull her back. "Martha, it would be too dangerous. I would risk destroying New York City—the planet—time itself…we already risked too much with the paradox we created. Come away, Martha, come into the Tardis. I'm so, so sorry."

She had never heard him this desperate. Maybe because he knew what she was thinking. She was thinking about the grave marker behind her, with Samuel Winchester's name carved in a solid block of finality. He was already dead, and she would spend the rest of her life without him. Unless…

"Doctor, the angel—will it send me back, back to the same place? The same time as Sam?" Her chest filled with cold, mist-laden air. She thought of this air as the last taste she would have of home.

The Doctor was at her side now, gripping her shoulders. "Stop it, stop this right now, Martha Jones. You can't-"

Martha raised her voice, afraid that his words would shake her too much. "Is it my best chance, though. To be with him? The angel might send me back and I could live with him—Doctor, I can't lose him again. Not the way I did before in the year he can't remember. I won't."

"Do it, Marty." She felt another hand. Dean, lifting her fingers to his lips and kissing them gently. "It's your best shot." His voice cracked, but he held her hand still.

The Doctor's frustration could almost be felt in the air around them. "Martha, the risks…you don't know where it will send you…"

The tears came now, fresh and hot. She took a shuddering breath, squeezed Dean's hand, and smiled. "It will be okay. Dean, take care of my mum, okay? Make sure she knows what happened. That I'm happy. That I'm with Sam."

"I will."

"Martha, please…"

It hurt like nothing really could to hear the Doctor's voice to broken, to feel his hand brush the back of her leg—he was kneeling on the ground now, she could tell. But she knew with incredible certainty that this was what was supposed to happen. As long as she was with Sam, everything would be fine. The Doctor didn't need her.

But she needed Sam, and Sam needed her—they kept each other whole.

"Doctor, I want you to promise me something. Promise me," she choked on her words, feeling the weight of them as she looked into the screaming face of the angel, "promise me that you'll find someone. Find Rose. Find anyone. Don't be alone for too long."

"Martha."

"Promise, Doctor."

It took a moment, because she knew that The Doctor had not prepared for her to leave so soon. And right now he would be blaming himself. Angry that he had not seen the angel, angry that he had let them linger in that graveyard too long, angry that he allowed Sam to see a gravestone with his name carved there. But the Doctor would be alright. He would survive, and he would understand.

"Martha Jones," he murmured, and this time his voice was broken but full of wonder and a deep sadness, almost like pride. "You were—you are—amazing."

The smile welled up like the tears and she let herself laugh. There was that tingle, that twinge of adventure—running into the unknown. This is what she was made to do. Giving Dean's hand one last squeeze, she turned to The Doctor and she winked.

"I know."

There was a sort of ripple of energy, and everything around her winked out of existence. The angel's touch had felt like heat and static and a whirlwind, and then she was stumbling dazedly on the pavement. She bent down, slightly sick, mostly afraid, entirely aware of a deep ache in her heart.

Then she heard his voice.

"Martha!"

And they were crushed in each other's arms, holding on like they could be torn away form each other at any moment. She buried her face in his jacket, gripped his clothes, held the back of his neck, cried hot tears, and listened as he said "I love you" over and over again.

This was how it was meant to be. Always.