The Doctor looked between the two Donnas. Now that he was closer, he could tell that they were different. There was something about the one nearest him that made him pause and swallow all of his usual retorts.
"Aye, we are," he said, calmly. He held up a hand, a gesture of peace. "Let's just think this one through...You don't want to hurt her. She's you."
He didn't, per say, know if that was true. These clones were an oddity, one that he might have liked to study further -- had it not been one of his closest friends replicating.
The gun took him off guard. He'd been lost in his thoughts on clones, about to say something soothing to Six, and then -- a gun was in the other Donna's hand.
It was like the entire world had skidded to a halt around him.
"You don't know what you're doing." His voice was sharp, emphasizing the harshness of his accent. His aversion to violence wasn't as strong as his predecessor. He had seen war, but this -- this was something different. "Aye, you think you do... but this.." He gestured between the two Donnas. "This is not the way."