The Doctor turned to the new arrival smiling brightly. "Hullo!" he said, waving with two fingers. He reached out to shake the man's hand.
He stopped, and doubled over as if he were punched in the gut. There was a sharp hissing sound, and his skin began to glow a goldish orange. He gasped in pain, and a yellow mist escaped his mouth. He fell to the ground, clutching his head as if afraid it were about to fall off.
Memories were flashing back to him. Death. Suffering on a Universal scale. The Time War. All accompanied by a guilt that threatened to overwhelm him completely, and drag him into the depths of darkness...
"Please..." he moaned. "Make it stop... I couldn't... I wasn't..."