He frowned, brow furrowing in confusion at the sudden angry glare from the Doctor that he found himself on the receiving end of. But just as quickly, it was gone and replaced by a more depressed and upset looking Doctor. "She's the only one of your lot who doesn't judge me for what I've done, or automatically expect the worst. Bill tried, but I know she'd been getting an earful from Jack about dangerous and untrustworthy I am. With River though, it's like she doesn't care. We're more similar than I expected and she's done her fair share of bad things too."
The Master paused as the Doctor approached him. "What other choice is there? I know who you are and what you're like, Doctor. I can be angry and resent what you've done, or get over it. Being angry won't get me out of here. It would just leave me alone." He shook his head and frowned. "And right now, I don't want to be alone. We both know what happens when one of us is alone for too long."