Ace pulled the trigger without even glancing in his direction.

 The Sixth Doctor fell to the ground, a smoking hole in his chest and a look of almost comical surprise on his face.

 "I hate it when people cheat," she said, grinning. "Come on, Professor, up you come." She reached out a hand and helped the Doctor to his feet.

 "You saved me..." muttered the Doctor, still a bit dazed.

 "'Course I did. That's how you see me. You know I'm still loyal, even after all the shit you put me through, because I know you've been through it with me, every step of the way." She gestured at the body of the Sixth Doctor. "That...and I'm not blind, and I'm not stupid. I know who the good guy is, and who the bad guy is."

 The Professor just touched her nose and grinned.

 After a moment, the Eighth Doctor arrived, panting for breath.

 "Well, you took your sweet time getting here," said the Doctor.

 "Me?" said the Eighth Doctor indignantly. He hadn't even noticed the garish travesty his clothing had become. "You're the one who got us into all this. If you'd looked at the TARDIS scanner to start with--"

 "All right, all right," muttered the Doctor. "Let's just get this over with so I can have some peace again--"

 "Aren't you forgetting something?" Ace interjected.

 "What?" both Doctors simultaneously responded.

 "Him," she said, pointing to the Sixth Doctor.

 When he spoke, it was in the voice of the Valeyard.

 "Did you really think that would stop me, either of you? I am a part of your essence, a memory of what you were and are destined to become. While you live, I will exist. I will return again, and again. I am your destiny, Doctor...sooner, or later."

 The Doctors looked at the Valeyard. Then they looked at each other.

 There was a stillness as loud as thunder.

 Finally, the Doctor looked back to the Valeyard. "This ends now," he said matter-of-factly.

 The Eighth Doctor looked at him as well. "You are desecrating the memory of someone very important to us. Someone we used to be. I think it's time that you understood that."

 He spread his arms, and power flowed into him from the Doctor. Arcs of lightning crackled between them as they shared perceptions, merged views. And finally, the Eighth Doctor took off his multi-coloured coat and flung it into the air.

 Someone caught it before it hit the ground.

 He was of an indeterminate age, somewhere between thirty and forty, with perhaps a bit too much good living contributing to a 'well-rounded' physique. His hair was a mass of sandy blond curls and his eyes glittered with amusement, not malice. He put on the coat as though donning a ceremonial robe, and walked over to the Valeyard.

 "You're not me," said the Sixth Doctor. "You aren't my essence, you aren't my soul. You're nothing but a pathetic, contemptible fraud, and I will not have you perpetuate this shambles any longer!"

 And with that, the Valeyard crumbled to dust, as though he had never existed.

 The Sixth Doctor turned to the others. "Thank you," he said.

 Ace made a meaningful coughing noise. "Oi," she said, "Care to explain to the token Earthling what this is all about?"

 The Doctor smiled. "Simple, really. My future self and I shared our perspectives. And since all he is--" he gestured to the Sixth Doctor, who puffed up indignantly, but said nothing "--is the perspective I have of him, re-centering that perspective restored him. You might say we took a more optimistic view of ourselves."

 "And your 'darker half'?"

 "Oh, still lurking about somewhere, I expect. It's not that easy to overcome, otherwise we'd all be doing it. But it won't be expressing itself in him anymore." The Doctor beamed. "And now, if you'll excuse me, it's been a long while since I've had a proper chat with myself." He and the Sixth Doctor turned to go.

 "Ahem," said the Eighth Doctor. "Aren't you forgetting something?"

 "Oh, yes," said the Doctor, slapping his forehead. He walked over and whispered something in the Eighth Doctor's ear, but even the most diligent eavesdropper could only have made out the words 'neither cruel nor cowardly.'

 "Is that all?" asked the Doctor, momentarily crestfallen.

 "Yes. Simple, isn't it?" replied the Seventh Doctor with a smile.

 He heard a voice say, "Secondary trauma. Soon be put to rights -- just like this castle." Castle? What castle? Who was he? Where was he? And why was it so cold in here?

 FIN