The entire foundation of the universe shook as someone grabbed Clara Oswald's hand and whispered, "Run."

I don't know where I am. I don't know where I'm going or where I've been. I was born to save the Doctor. But the Doctor is safe now. I'm the impossible girl, and my story is done.

The entire foundation of the universe shook as someone grabbed Sam Winchester's hand and whispered, "Run."

I don't know where I am. I don't know where I'm going or where I've been. I was born to put the impossible girl back together. But the impossible girl is whole now. My story is done.

The entire foundation of the universe shook as someone grabbed Dean Winchester's hand and whispered, "Run."

I don't know where I am. I don't know where I'm going or where I've been. I was born to restore the DoctorDonna. But the DoctorDonna is gone now. I'm the Most Important Man in the Universe, and my story is done.

Dean surfaced outside of the time stream. He was laid out in between Sam and Clara. His head felt fuzzy, and it took several moments for his vision to come into focus. He sat up carefully. The roar of the time stream had faded to a buzz. The Doctor was sitting before the three of them, his face gloomy. Dean didn't say a word.

Sam stirred, and sat up quickly. "Where is she?" he croaked, pressing the heel of his palm against his forehead.

Dean was confused by his brother's sudden concern, but the Doctor seemed to understand. "Clara is here," he said, and he moved to her side, where she was starting to awaken also. Dean noticed how his voice sounded smooth as ever, yet Dean could tell that something had broken inside of him and would never be the same.

Then again, Dean would certainly never be the same either.

Dean rose to his feet and held out his hand to his brother. "Come on, Sammy," he said, his voice scratchy. Sam took his hand, and in turn offered his hand to the Doctor and Clara.

The four of them went to the door of the TARDIS and peered out, immediately regretting it as they took in the sight before them.

Angels lay slaughtered on the ground, shadowy impressions of wings overlapping bodies. River, Jack, and Cas stood in the midst of all this, their backs to each other in a defensive position that they were reluctant to let go of. At the sight of the Doctor standing at the entrance of the TARDIS, they relaxed. They skirted around the edges of bodies until they joined their fellow companions inside the walls of the TARDIS. River let out a breath she must have been holding for a while. Jack, unscathed, helped an injured Cas sit down.

"I think we deserve an explanation, Doctor," River said.

The Doctor only nodded as he entered coordinates into the TARDIS. They traveled through time and space before landing, but instead of leaving the TARDIS, the Doctor stood at the door to face the others.

"Donna-Lucifer-went into my time stream to rewrite history and destroy the universe," the Doctor said heavily. "That's where Clara, Sam, and…and Dean came in." His eyes locked with Dean's and remained that way as he spoke. "Clara…fixed everything. And Sam…fixed Clara."

"Fixed me?" Clara whispered. "How does that work?"

The Doctor rubbed his hands over his face. "The whole situation is…complicated. Imagine that you were a puzzle, Clara, and each piece of you was scattered somewhere in my timeline, helping me simultaneously throughout my entire history. Sam, he…he went through each step of my history, finding each piece when its work was done, and put the puzzle back together. Which is why you're here now, Clara, instead of being ripped apart for all eternity across the universe."

Clara scuffed the ground with her shoe. "Well, when you put it like that, I suppose I have to say thank you." She looked up at Sam and gave him a half-smile.

"Saving people," Sam muttered. "It's what I do."

"Hold on, then what was Dean doing there?" Jack asked. His face was pale after all that he had done, but his voice didn't waver.

The Doctor murmured quietly, "I don't know what happened, but I can guess. But this is something that Dean would have to tell you himself."

Six pairs of eyes turned to Dean. Dean swallowed uncomfortably. "I can…I can tell you that it was all about the…the whole…DoctorDonna thing."

He looked at each of them individually. The Doctor knew more than he was letting on, Dean was sure, but didn't want to say anything because this was Dean's problem, Dean's moment. River and Jack were morbidly curious, he knew. Sam would want him to open up, and not bury his feelings, but this…this was something he could never explain. Cas understood. Of course Cas understood. Dean could see it in his blue eyes. But it was Clara, sweet Clara, who said what needed to be said. "I think it's better left alone." She stood beside him, and reassuringly placed her hand on his arm.

Sam made a face like he was about to argue, but a soft touch on his arm from Clara quieted him. The Doctor and Cas both nodded, while River and Jack exchanged a look but resigned themselves to not knowing.

"All you need to know, then, is that it's over," the Doctor clarified.

"So where have you taken us, Doctor?" Jack asked.

The Doctor jerked his head at the TARDIS door. "Go take a look."

Jack, River, Cas, Sam, and Clara all made their way out the door, but the Doctor shut it before Dean left.

"I'm sure you have questions," the Doctor murmured.

Dean shrugged helplessly. "I barely even know what happened," he admitted, "except I feel guilty. I feel guilty because I couldn't stop…what happened to her."

"It's best you know now that this was not your fault." The Doctor ran his hand through his hair. "There are fixed points in time, things that must happen, and will always happen, no matter what other details in time are changed. It's practically written in the stars."

"That doesn't make it feel any better."

"No, I suppose it doesn't." The Doctor took a few agitated steps toward the center of the TARDIS again. "I can't offer you every answer, but I can tell you this. This whole ordeal was never about Michael and Lucifer. It was about the Most Important Man in the Universe, and the Most Important Woman in the Universe, coming together to prevent the whole of reality from being destroyed. Donna sacrificed herself by becoming the DoctorDonna once more. The memories were so powerful that they burned her up, and…and everything inside of her, too." The Doctor suddenly took Dean's face in his hands, and Dean first noticed the tears that had been rolling down his cheeks. "You triggered it. You triggered Donna to fight out of Lucifer's grip and rediscover her memories. You were always meant to be there, because you are the best hunter in the world and the only one who could have tracked her down through my time stream. It was always you, but that doesn't mean it's your fault. You saved the universe, Dean Winchester."

"I don't feel like it," Dean said through gritted teeth.

The Doctor offered him a watery smile. "I've saved the universe plenty of times, they tell me, but I'll be damned if I ever felt good about it. Because it always comes with a price, and usually the price is the life of a friend."

"That's not fair."

"It isn't, is it?" And with that, the Doctor opened the door and beckoned for Dean to come out with him.

Dean was shocked by the icy wind and snow that hit him. The other five were shivering but stoically not saying a word. Dean realized they were listening. A song was floating through the air, and it grew louder as Dean focused in on it.

"This is the song of the DoctorDonna," the Doctor said. "We are on the planet of the Ood, where they promised to sing of her always."

Dean was enchanted by the haunting melody. He couldn't understand the words, but he could understand the feeling that was rushing through him. Loss. Sacrifice. Grief. And hope. Just enough hope to get him through today. Maybe even the next day. After that, well, who even knew?

The Doctor stood at the head of the mismatched, ragtag group, his eyes closed as the music wafted over him. River stood at his right shoulder, her curls tangling in the wind. Jack stood at his left shoulder, the life and energy haltingly returning to his face even in the bitter cold. Sam stood over Clara, shielding her from the snow. Clara seemed confused but not opposed to his close proximity, throwing him a glance and a sad smile every now and again. They were going to be fixtures in each others' lives from now on. Dean brushed by Cas, and they stood shoulder to shoulder, turning their heads to gaze at each other for a while before lifting their heads to hear the melody.

And know this, DoctorDonna. You will never be forgotten. Our children will sing of the DoctorDonna. And our children's children. And the wind and the ice and the snow will carry your names forever.