The Doctor leaned forward to pick up his glass and took a sip before speaking again. "I haven't heard anybody call him Saxon in a long while." But he accepted it without question; after all, 'the Doctor' wasn't his real name, and neither was his 'creepy friend' really 'the Master'.
"I wouldn't be surprised if he'd come across these Monks before, or knew how to stop them. His travels throughout the universe took him to different places than I. But there's one thing you need to know about the Master, he's straightforward to a fault, and he often lacks empathy, but most importantly, he loves to watch people squirm, so he'll tell you something disturbing to you on purposely. Or, more to the point, to disturb me. Because if he gets into your head, then he know that will make me upset." He grimaced a little. "Things are not always so black and white. There's got to be more than one way to stop these aliens that doesn't involve any bloodlines ending."
Because the Doctor understood what Bill had suggested, that for the Earth to be saved from the Monks, she would have to die. And that was an option the Doctor was not going to accept.