"It's simple, really. Just being around me is putting you in danger... I should be alone."

He wished he had the TARDIS at his hands, to be able to actually make that possible and not worry that he's endangering anyone. He saw Jubilee just a couple days before anyone realized she was gone, and he knew the scientists had been watching her very closely thanks to him. Donna had asked him if he thought something was going to happen, and it did, to her; he should've seen that coming. And the man that tried his hardest to save her perished in the process while the Doctor was completely and utterly useless? He was complete rubbish.

As much as he hated to admit it, he feared that Mina was next.