Whether it's a good cry or a bad one, sometimes a cry is needed. The song is a short one, but it's alright, the Doctor lets it drift into silence, though will hum it again if Eight needs it or something else.

"It's for a friend," the Doctor says after a while. "That I haven't seen in a very long time." Like all her friends really. Eventually. But she's lucky to be able to make so many.