A/N: Written for the Daily Prompt over at the TARDIS challenge forum. The prompt was "Secret Diary". I immediately thought of River's diary. :3
Disclaimer: I do not own River Song, the Doctor, or Doctor Who. They are property of the BBC. Forest of the Dead was written by Steven Moffat.
"When you run with the Doctor, it feels like it will never end. But, however hard you try, you can't run forever. Everybody knows that everybody dies, and nobody knows it like the Doctor. But I do think that all the skies of all the worlds might just turn dark if he ever, for one moment, accepts it."
~River Song, Forest of the Dead
The Doctor had seen many people die throughout his long, long life, but River Song's struck a chord deep within his soul. She knew him, the future him. She knew his name. She'd given herself for the world, to keep him alive for the future. River kept a diary with his, her, their future written inside. She was elusive, she trusted him, she intrigued him.
The urge to peek inside that blue book was enormous, almost overwhelming. She'd mention the Pandorica Opening, Crash of the Byzantium, adventures he had not yet been on. If he looked upon the future, he'd know what to do, how to save everyone. But then he'd know what'd happen, who died for him. He didn't want that.
So he left her little secret blue book in Biographies. Perhaps, one day, he'd return and read the words she had written. But for now, it was as much of a secret as she was. As he walked away with Donna back to the TARDIS her heard his final words with her.
"Funny thing is, this means you've always known how I was going to die. All the time we've been together, you knew I was coming here. The last time I saw you- the real you, the future you, I mean- you turned up on my doorstep with a new haircut and a suit. You took me to Verilian to see the singing towers. What a night that was. The towers sang and you cried. You wouldn't tell me why, but I suppose you knew it was time. My time. Time to come to the Library. You even gave me your screwdriver. That should have been a clue. There's nothing you can do. "
"You can let me do this!"
"If you die here, it'll mean I've never met you!"
"Time can be rewritten!"
"Not those times. Not one line. Don't you dare! It's OK. It's OK. It's not over for you. You'll see me again. You've got all of that to come. You and me, time and space. You watch us run."
"River, you know my name. You whispered my name in my ear. There's only one reason I would ever tell anyone my name. There's only one time I could…"
"Hush now. Spoilers."