I was a dad once. But I wasn't just a dad, I was a grandfather.

Susan.

She was a beautiful girl. Smart. That girl could run circles around any of those professors at the college. And yet she was so sweet. Naïve, almost. Her smile was almost impish; as if she knew all the answers you were searching for. But she was quite the smart aleck, as well. Why she chose to come with me, I'll never know. She could have been someone back on Gallifrey, could have taken one of those stuffy jobs, led the people, done all the right things…and yet she didn't. She gave it all up, just to wander around the universe in a stolen TARDIS that didn't even work properly. She was so much like me. She didn't want the wealth or the fame, she didn't want the responsibility. She just wanted the freedom. The ability to explore the cosmos and never have to follow the rules. She was so much like me.

And I killed her.

I never meant to leave her for so long, I only meant to make her think a little. She was so frivolous sometimes. But I never did go back for her. I wonder if she would have even been there if I had. But it's too late now. She's gone. I doubt she'd even recognize me if she were still here. It never changes much with any of the people I travel with, the pain of parting, but with her it is still so much harder. She was different. She was blood.

She must have thought I hated her, leaving her like that. But I didn't. I don't. I never will. She is, and forever will be, my granddaughter.

My Susan.