"Maybe you're thinking too hard and should stop saying stupid things," the Master grumbled. He sighed and rubbed his short hair, then sat down on the floor. "You're good at upsetting me. Always have been. You're wrong though, Doctor. I don't mistrust you. I'm frustrated and angry with you, but if I didn't trust you then I wouldn't still be here. I would've bolted the moment you let me out of the TARDIS."
The Master tilted his head back and gazed up at the ceiling. "She's right, you know... about me. That's the perfect analogy for how I feel most of the time. Like I'm still in the Time War. Angry, scared, frustrated, and just... broken. I'm tired of fighting, Thete. Especially with you."
He closed his eyes, just listening to the quiet humming of the TARDIS and letting the sound calm him down. "You want me to be good. You want me to be more like you. To be more like her. But sometimes I don't even know who I am. Compared to my other regenerations, I feel like I've barely even lived. Just a short couple of human years and Lucy killed me. Then I was reborn and only had a couple of days before I was dragged back to Gallifrey. And now here I am."