A planet without life? Really? Oh, well, I don't believe that for one moment — planets always have life, unless they're the sort that don't and then that's because it'll kill you. Well, not you you, but life. A sort of — defence mechanism.

[ The Doctor sets his mug down and decides, yes, this really would go well with some biscuits, so he's going to do just that.

Look for biscuits. There must be some around here. ]

You never find an empty planet, not unless it's because something else has happened to it. Suppose that ruins the story though, doesn't it?