"It's a wonder ship. She's called the TARDIS. Time and Relative Dimensions in Space. We can go anywhere, anywhen. It is hard, but y'know?" Donna heaves a sigh. "Lived without it most of my life. "My friend's the one I really miss, and I'm worried about him. He doesn't do very well on his own. Needs someone there to help... temper him." That's probably the more diplomatic way to put it.

"But while he's away, might as well brush up on a few new skills." She listens attentively. "Assuming the stacks are just you portioning things out? How d'you decide the right portion?"