Which came first, the phoenix or the flame?' 'Hmm . . . What do you think, Harry?' said Luna, looking thoughtful. 'What? Isn’t there just a password?' 'Oh no, you’ve got to answer a question,' said Luna. 'What if you get it wrong?' 'Well, you have to wait for somebody who gets it right,' said Luna. 'That way you learn, you see?' 'Yeah . . . Trouble is, we can’t really afford to wait for anyone else, Luna.' 'No, I see what you mean,' said Luna seriously. 'Well then, I think the answer is that a circle has no beginning.' 'Well reasoned,' said the voice, and the door swung open.