"Well, who else would it be?" he said, with his typical wide-eyed look of bafflement. "There aren't any other blokes wandering round in a big blue police box, are there?"

The joke was something habitual, really. It was too much of a habit for him to hide behind his jokey face; besides which, it was wonderfully easy to slip back into the old ways of always laughing and joking. He knew they'd have to be serious and honest later. But that could wait until they both had chips.