River gripped the Doctor's arm.
"Come on," she said. "Doctor, come, now. Into the TARDIS."
He tried to shake her off, but she would not let go, would not let him sit and wallow. Not here. Not yet.
"Doctor, please." She was begging now, begging like he had just moments before. But it was for his own sake she called the retreat, rather than for her own. For his own good, she could not allow him to stay at this spot, the spot where he had lost Amelia Pond.
For his own good, she had to force him to move.
He did, finally, get to his feet, although there was no energy in his movements.
"That's it," River crooned. "That's it. Come with me, now."
She walked backwards, keeping his face on hers. Although it hurt her to see the pain in that face, in those eyes, any pain she felt was secondary to his. It had to be. And contrary to warnings of previous days, she couldn't afford to allow him to look back at the figure by the gravestone.
The TARDIS doors opened for her, as they always did. She took the Doctor inside and led him over the threshold, up the ramp, and into the chair. The ship was humming softly; it was a safe atmosphere for him, there in the TARDIS's care. But safe wasn't good enough yet. There was still something that River had to do.
"Wait here," she gently ordered. "I'll be right back. Just sit here and stay calm."
He didn't ask where she was going or what she was doing as she left, but that was fine; she didn't want to have to answer those questions.
River pulled the TARDIS doors open and stepped through, quietly closing them behind her again. She was not surprised to see the Angel still standing there by the gravestone. It had shifted to the left a bit and hits hands were now down at its sides, but other than that it had not moved, even though no eyes had been on it for some time. River slowly approached the Angel, carefully avoiding direct eye contact as she studied its face.
"What am I to do with you?" she asked. There was no response; the stony face remained so.
What was odd, however, was the expression on that face. All the Angels that River had ever seen had either looked angry, teeth bared and threatening, or pleased, like the haunting smile the Angel in Winter Quay had. But this one was neither. Its face looked blank. In a human, River would have said that it looked uncertain, or even nervous.
This was the last Angel, one that had somehow escaped the paradox, probably because it had been here, in the cemetery, where all would come full circle in the end. All the others were gone.
All of its sisters were gone.
One Angel, suddenly all alone. Weak, hungry, and afraid. Of course it had struck, not for pleasure or vengeance, but because it was desperate.
"I understand," River said. She could understand desperate; she had experienced it herself time and time again.
But was her understanding its motive enough reason for her to let it go? It had taken Rory, taken Amy. It had hurt the Doctor in a way that River doubted she could fix. It had hurt her, too, in taking her parents, but she couldn't allow herself to think about that, not yet.
It was bigger than that, even. The Angel was a danger to the humans here. It could destroy countless other lives in its quest for survival.
What, though, could River do? She couldn't take it anywhere else; letting it onto the TARDIS or even near her Vortex Manipulator was too much of a risk. Letting it anywhere near the Doctor was also too much of a risk; although it was terrible for him to grieve, it would be worse for him to be given a chance to turn to revenge. Whatever fate the Angel got, River had to do it herself, there and then.
She thought back to the Angel in Grayle's mansion, with chips taken out of its face and fingers broken off. She remembered how it had screamed.
Once, she would have taken pleasure in making someone scream like that. It had been one of her few sources of entertainment. But that was when she had thought that pain was the only thing that the universe had to offer her. She had been young, angry, and very, very foolish, but she hadn't realized it until that day in the restaurant in Germany. The day she'd almost killed the Doctor. The day she'd almost destroyed her one chance of a future that was not just made of pain, but instead would have joy, adventure, and love.
For the rest of her life, she had determinedly backed away from that day, trying to make amends, trying to cover her tracks, trying to grow up. And she had. There had been slips, of course, usually in moments when the Doctor had come to harm. But overall she was no longer the weapon that Madame Kovarian had created. She was River Song.
But now River Song was standing face-to-face with a Weeping Angel, contemplating the idea of slipping again, of making the Angel suffer for what it had done.
For what it had had no choice but to do.
It was such a terrible thing to be dangerous, afraid, and alone in the world.
And there had already been so much sadness and pain that day…
"I'm sorry," she said. Then she turned around and walked back into the TARDIS.
The Angel did not chase her. It watched her leave. It stared at the blue box until it had faded into the air.
It is impossible to read the mind of a statue. Perhaps the Angel wondered who the people in the graveyard had been and where they had gone. Perhaps it wondered how long it would live, alone on Earth with only occasional sustenance from human potential energy.
Perhaps it wondered why, when River Song had stood by her parents' gravestone and the time had come to decide, the child of the TARDIS had left an Angel to its own fate.