The Doctor supposes it’s time he came clean about why he left Jack behind. He should explain, but he keeps putting it off. “I was busy.” It’s really no answer at all, and certainly not what Jack wants to hear, but he won’t like the truth any better.
Why would he? Although, he takes it better than the Doctor would have expected. “I left you behind on the game station deliberately. You’re wrong,” he tells his former companion. “You’re a fixed point. You shouldn’t exist. It’s not easy even looking at you.”
“So you’re saying you’re prejudiced?”
Maybe he is.