"I suppose I'd better be off, then," the shorter man said, doffing his hat. "Ace'll be wondering if she blew up the TARDIS. Again."
The taller, leather-clad one nodded. "You got rid of the query-marked jumper," he said.
"Yes, it did look a bit ridiculous," the shorter man said. "The umbrella should be quite enough of that. Stylish and functional!" He regarded his counterpart a moment.
"Get a grip on yourself, will you, old fellow? Don't do anything rash."
His older self gave him a sad smile. "Already did." The smile was replaced by a grave expression. "You're gonna die, you know."
The smaller man's smile faltered, but didn't vanish.
"Well, I expect so," he said, "after all, here you are!"
To his astonishment, his older self fell to his knees. He could hear him start to sob out, "Why did I... Why..."
He dove into his TARDIS, slammed the door, and started hammering on the controls.
He saw what had happened. In this incarnation, he had an amazing talent for seeing the bigger picture. For manipulating his way to victory.
By Rassilon, that was one future he was going to prevent.