I do not own Doctor Who or any of the characters therein. And I'm going to warn you that I teared up while writing this… and again proofreading it the next day.
"So, where are we then?" River asks, attempting to downplay the situation.
"I just dropped you back off at Stormcage… after the Singing Towers." The Doctor has trouble meeting River's eyes as they watch him from the information node.
"And you knew," River says. Not accusingly. Not judging. Not reprimanding. She just says.
The Doctor licks his lips as if they were chapped. "Yeah. I did."
But… what? No- why?
"Then why?" Still not judging.
"Because this was the first time I met you, River. If I hadn't met you here… If your message hadn't gone wibbly… We would never had met."
"What about Messaline? The Angels?"
He smiles slightly, still not meeting her eyes. "First thing you said to me here?"
"Only reason I knew it was you."
What does he mean? How- why- how could he let this…? No… But maybe…
"So how long do you think it will take you then, sweetie? Cal's upped the firewalls and defenses since you were here last- didn't want to take the chance that the Vashta Nerada would start having a taste for circuitry. Bit of a farfetched idea if you ask me, but that's what you get when a child-"
"I can't," he says suddenly, interrupting her before she can go much further.
River blinks in surprise. "What do you mean- 'can't'?"
The Doctor stares at his feet, rubbing his cheek with his hand. "I mean I can't save you. Not this time."
But he always saves everyone. Even me. Even when-
"Why not?" A slight accusation. Not harsh, but enough to make him flinch.
Finally working up the courage, the Doctor looks River in the eyes. "Because you're… you. You're River Song. You're the child of the TARDIS."
But shouldn't that mean that he should be able to…?
"The Library's programmed with information of all known living species and genetic patterns," The Doctor explains, moving to stand in front of the console once more. "Judoon, human, Raxacoricofallapatorian, Ood… But not Time Lord."
"And," he says, staring at the keyboard once more, "certainly not human plus Time Lord." His green eyes, a film of tears forming on them, flick back to River. "Do you understand?"
"No," a third voice says.
The Doctor jumps and then sighs. "Oh, Rory…"
Slowly, the Last Centurion walks over to the statue with his daughter's living face on it. The daughter he just barely knows.
"Doctor, what happened to her?" he asks, reaching up to touch River's face. "What happened to you?"
Biting his lower lip, the Doctor comes over and stands next to Rory. "There was a group of people. Brave people. They came here to the Library to see what went wrong 100 years ago. All they had was a data fragment. '4022 saved. No survivors.'"
"And I was their guide," River says. "Doctor of Archeology, remember Dad?"
"We found out that the library systems had literally saved them all- to the hard drive. But things got, well…."
"Complicated?" Rory says, his eyes never leaving his daughter.
"And I saved them," River explains with a proud yet sad smile. "Let the computer borrow some extra space. Not exactly something you survive intact. And this impossible man found a way to save me."
"Well, you did just remember what to do given what you found but-"
"No," the Doctor says, fists tightening, "I only sort of saved you. I can't get you back." Whirling on one foot, he returns to the computer console and grips the edge, refusing to look at anyone. "Cal could save known genetic patterns. That's why everyone was able to be downloaded out of the hard drive. But only known ones. And you-"
"And I," River continues, now realizing what the Doctor is saying, "am not a known pattern. Human plus Time Lord. Not exactly what you'd call common."
"No," the Doctor whispers to no one in particular.
Rory simply stands, still looking at his beloved daughter, processing it all. A single tear rolls down his cheek.
"There's nothing you can do?" he asks the Doctor, just slightly looking over his shoulder at the bowed and defeated figure at the computer console.
"No… I'm sorry. I'm so… so sorry." His grip tightens on the console as if it's the only thing keeping him sane. "Even if I tried to actualize what little the computer and sonic were able to save… She wouldn't survive. She's older than you think, Rory-"
"I am still here, thank you."
"Even without regeneration, Time Lords live extraordinarily long lives. The Time Lord plus wouldn't translate and without that to stabilize her…"
"I wouldn't make it. I may live in a virtual reality, but it's life. I was taught never to give up on that."
"Who taught you that then?"
"Who do you think?" River says, looking at her love. The Doctor looks up, still struggling to keep control. River smiles at him. A smile of forgiveness. Of understanding. With a sniff, he goes to stand by Rory once more.
"Oh, it's not goodbye. I think you've still got a few more adventures to catch up on, sweetie." She winks at him. "Dad, look after him… and tell Mum… Tell her that I love her. I don't want her to know- she's been through so much with me already."
"'Course," Rory says. Standing on tiptoe, he gives his daughter a kiss on the cheek. With one more sad smile, he turns to go. "I'll- I'll just let you two alone. Need some time to think of something to tell Amy, anyways." The door soon swooshes shut and the Doctor and the Professor are alone.
"I am sorry River. I wish-"
"I know." River licks her own lips. "And you're forgiven. Always and completely forgiven."
"So what will you do?"
"Oh, you know. All of history and fiction to live in. Think I might try the fantasy section for a while. There's a 21st century cycle I've always wanted to read. What about you, Doctor?"
"Oh, same old life," he says. Echoes of an all too similar conversation surface in his memory.
"Take care of yourself, sweetie."
Standing on his own toes, the Doctor and River kiss. Not a passionate one as they were once wont to do, but a simple kiss of two people who know and love and understand each other possibly more than they do themselves. With one last smile, River's face melds back into the statue and she is gone.
The Doctor stands there alone, eyes closed and head bent.
Why must it always end this way?