He wouldn't have been surprised if his reaction to the mention of the Master's old name had been visible and apparent. Perhaps that jolt of anxiety and grief he felt had been an physical flinch, or perhaps the sinking feeling showed itself in his face. Either way, he couldn't help but react especially being told about a kidnapping.
"Oh..." he whispered softly; it seemed like so long ago now, another universe practically. "Mm, has had, I'd expect. He's dead. Refused to regenerate, died in my arms. I cremated him," he told her, rather matter of fact about it. He'd rater seem callous than like an emotional wreck. "I think.. well, I basically know... that you've been pulled out of your personal timeline," he said, hardly daring to ask the next question. "Where did you just come from? Where... and when where you last?" he asked anxiously, trying to maintain eye-contact and act less distracted.