"What exactly is peaceful and relaxed about the 20th century?" Jack asked incredulously. "The first two world wars took place in the first half of it! Really, Doctor, you've got a funny idea of relaxation." He rolled his eyes and added to himself, "No wonder I like hanging around with you."

"Right," he said, tapping both hands against the console, "we can do Earth if you want to do Earth. Just do me a favour, no London and no Cardiff. Trust me, that wouldn't be a good idea for me."