While The Master's evidence was..compelling, to say the least, The Doctor was unwilling to agree to any position of innocence. "Whatever you've done, whatever you're doing, however you're here, I will end it." Despite any doubts that may have begun to bubble, even the slightest bauble of an idea that The Master was, in fact, innocent in any of this, was not something he'd be willing to listen to - at least not now. The Master, however, had spoken of 'later' and, considering his future, regenerated, self was also about, it was a piece of information he was at least willing to tuck away for later, spoiler or not.
"..Why did you pick Delaware?" He had to admit, it was a good question. "Sure, remote, out of the way and..." The Doctor's voice trailed as the bright city lights from Metropolis struck his eyes. It was, clearly, a city teeming with wonders that were quite out of place. The Doctor turned his gaze back down to The Master. "I don't suppose it would have anything to do with the bright, shiny, clearly out of place, and technologically advanced city sitting right over there?" Despite the comical tones it was a clear accusation. There was nothing about The Master that The Doctor was willing to trust, at least not then, not in that moment.
"We all die." He added grimly. "Even a Time Lord isn't meant to live forever and you, you've cheated death more than most of us." Which the man, really, couldn't argue. Ever since the beginning, The Master had been an insidiously clever man, manipulating people, time, and events in ways The Doctor had to begrudgingly admit surprised him, if just a little. "And yes, I'd heard." If it had been anyone else, anyone, that would have been a great time for a joke, but he was in no mood. "Necrotic reanimation - hardly a pleasant thing." He clipped his words, never once taking his eyes off the man.
His words, their placement, it seemed almost too convenient. If The Master really was implying that he was behind it, which certainly seemed to be how it sounded, then why would he have made a claim of innocence? The Doctor's brows knit together as The Master, again, claimed ignorance to the events around them. It was confusing, but it wasn't outside the realm of possibility. Still, the man was dangerous and The Doctor knew better than to ever take his eyes off a dangerous man.
"How did you get here then? Tell me what happened. Convince me."