Ah, yes, she'd forgotten. Some people like to walk and talk, the Doctor is apparently the sort to walk and elaborate. (She would've loved a professor like him in Hogwarts. She would've hated one too - all that chaos.)

"So, essentially we improvise," she points out, with one raised eyebrow, even as she follows him to the water.

"It beats doing the same thing over and over and expecting different results," she says, with a sigh, and picks up her pace. The water. Business.

(Wait, she has a fact:) "That'd be the definition of insanity, according to Albert Einstein, you know?"