I turned slowly to see him walking up the stairs. Alive, back to normal, safe. I smiled and started running towards him.

'Doctor!'

'Hello.' His odd tone stopped me short. There was something off about the way he was standing, too, and his smile…it was fragile. His eyes threatened to break.

'You're young again.' My voice trembled slightly, unsure of itself. 'You're ok.' It wasn't quite a question, but it demanded confirmation.

Confirmation that I wasn't receiving.

'You didn't even change your face,' I said, half-joking, still waiting for him to grin and whisk me off across the universe like nothing had happened.

He laughed, and I thought I could relax when he said, 'It's started.' The panic started to rise in my chest as his voice quickened too. 'I can't stop it now, this is just the reset.'

My smile vanished.

'Whole new generation cycle – ooh!' He picked up the bowl of fish fingers and custard and downed it in one, making a sound of contentment. I couldn't help laughing – he looked so ridiculous. I turned away, trying to keep the tears from my eyes, trying not to let him see me cry. I should've expected his attempt to make me laugh.

'Taking a bit longer,' he continued, setting it carefully down. His eyes twinkled. 'Just breaking it in.'

He started making his way around the TARDIS, grunting as he did so. He was in real pain. He thrust a lever down, pushing another up, just like he always does. But this time was with so much effort, as though he were old and tired again.

There was a moment of silence – me watching him, heart feeling as though it were teetering on the edge of a cliff, and him staring into nothing like nothing made any sense.

'It all just disappears, doesn't it?'

I stared at him, unable to make a sound.

'Everything you are, gone, in a moment, like…' His fingers reached for something invisible to the both of us. And then he caught it. Well of course he'd catch it. And his eyes lit up, his entire face, like a child's at Christmas. 'Breath, on a mirror.'

It was a beautiful way of putting it. But all I could do was look at him, heart filling with dread. I could practically hear his two hearts ticking their last and this couldn't be happening. The Doctor carried on, oblivious, and all I could do was watch.

He held my gaze, eyes still sparkling, fingers still pinching at something so precious, so special, like a secret he thought we shared. 'Any moment now…' He almost laughed. 'He's a-coming.'

'Who's coming?' My voice broke.

If this was a joke I didn't get it.

The Doctor just looked at me, almost paternally, still smiling. 'The Doctor.'

'You,' I whispered. My blood pushed me on, stronger, 'You are the Doctor.'

'Yep,' he croaked, keeling over slightly. I wanted to help him, but my legs were frozen. His eyes stared into mine, both of ours filling with tears. His almost seeming to be saying, it's alright. It's ok. But that was ridiculous. He'd be lying. This couldn't be goodbye. I wouldn't let it be.

He straightened up, shaking, and managed, 'And I always will be.'

The pride in his voice…thick with sadness. And even then it was like he was trying to comfort me. But I didn't want comfort – I wanted him. More than anything, ever, I wanted him to stay. Doctor…He was the only thing in my thoughts. The only thing, and the whole of him, nothing else. Nothing else mattered.

He lifted his hand, which glowed gold. 'But times change,' he said firmly, the tension in his voice building. His tears were real. Tears he was trying so hard to hold back. 'And so must I.'

I looked at him tenderly. I'd never loved him so much. He was so brave; he'd always been so brave. My smile wavered as my own tears threatened to fall. The lump in my throat was not going away, and I knew this was going to be it. There was nothing I could do. I could try my best not to cry and fool no one, but…I didn't want him to go.

Suddenly the Doctor turned his head. His ancient eyes followed the TARDIS stairs up and his face changed. 'Amelia!' He said the name like he was calling it, and like it was the most important name in the universe.

I turned, trying to see who he was talking to, but there was no one there.

'Who's Amelia?'

He was still looking, eyes tracking something with urgency and joy. He didn't even look at me when he answered, 'The first face this face saw.' For a moment the tears had stopped. He looked so happy, almost grateful – completely lost in some memory, or hallucination…or both. No. I shook my head slightly, trying to jerk away the flood of angst from taking over, seeing him like this, so full of life and hope, knowing that he was about to lose himself any minute. That I was about to lose him. This couldn't happen. This couldn't be it. No, please Doctor, please… Don't say goodbye.

He turned round again, arms outstretched, face calmer and more peaceful than perhaps it'd ever been.

'We all change,' he said softly, and it was like he was easing a great weight off his chest as he spoke. His expression took on that of a man who had so much wisdom, who had seen so much, that it was hard not to fall right there. 'When you think about it, we are all different people, all through our lives, and that's ok, that's good, you've gotta keep moving, so long as you remember all the people that you used to be!'

I just looked at him, unable to comprehend how he could be so unruffled, even energetic, working himself up over some concept that couldn't possibly matter now.

He clapped his hands together at last. 'I will not forget…one line of this. Not one day. I swear.'

He looked at me, and I at him, speechless.

And then he said something I'm sure will stick with me for the rest of my life.

'I will always remember when the Doctor was me.'

I opened my mouth to speak, but nothing came out. I watched as his shoulders started to fall, but then he saw something, and he looked up. His face took on one of shock, but a pleasant shock, and then he raised his hand to caress the air.

Another illusion? At first I thought it could be River, but that was impossible. The Doctor had already said goodbye to her, and the way he smiled was different. Who then? The moment was gone too fast, and the Doctor lowered his head, arm dropping to his side. Whoever he'd seen was gone. I stepped closer as he slid his bow tie from around his neck and inspected it one last time. Then he let it fall. His final act of farewell. The bow tie crumpled against the cold metal floor and panic consumed me.

I wished I could make him stop. This if anything else showed me that the Doctor was giving up. That it was all over, and he was just accepting it. No. Doctor, no.

He smiled at me then, before squeezing his eyes shut and grimacing in pain.

'No, NO–' I rushed forwards, tears streaming down my face, reaching out to grab his hand.

'Hey,' he breathed, eyes open and looking into mine again, stopping me.

Didn't he know I couldn't take it anymore? I stood with my fingertips outstretched, still longing to bring him back before it was too late, eyes beseeching him to help me, to help us both. I wanted to hold his hand. Just to touch him and never let go.

But I'd never touch him again.

I didn't know what to say. I didn't know how to say it.

I couldn't do anything.

My expression pleaded him to stop.

I was about to lose him forever and there was nothing I could do.

I kept my hand almost touching him, barely maintaining enough willpower to keep a distance at all.

He didn't even see what this was doing to me.

Loving him didn't matter, because he was going to go. I'd never see him again. But I loved him anyway.

And right to the end, my eyes never left his face.

'Please don't change,' I whispered.