The Doctor's face split into an excited grin. From one adventure to the next and no stops in between. He was addicted to adventure, and in a way that couldn't have been fair for Jack, who clearly needed a break.

Jack was ready to die the night before, he reminded himself. It wasn't fair, tossing him back into this, now.

He controlled himself.

"Nah, you know what? I'll take a look into it, you stay here, keep an eye on the TARDIS."