Argue with anything else, but don't argue with your own nature. - Philip Pullman

Dust is not a constant. There’s not a fixed quantity that has always been the same. Conscious beings make Dust — they renew it all the time, by thinking and feeling and reflecting, by gaining wisdom and passing it on. And if you help everyone else in your worlds to do that, by helping them to learn and understand about themselves and each other and the way everything works, and by showing them how to be kind instead of cruel, and patient instead of hasty, and cheerful instead of surly, and above all how to keep their minds open and free and curious…Then they will renew enough to replace what is lost through one window. So there could be one left open.

It was a shocking thing to say and I knew it was a shocking thing to say. But no one has the right to live without being shocked. No one has the right to spend their life without being offended. Nobody has to read this book. Nobody has to pick it up. Nobody has to open it. And if you open it and read it, you don't have to like it. And if you read it and you dislike it, you don't have to remain silent about it. You can write to me, you can complain about it, you can write to the publisher, you can write to the papers, you can write your own book. You can do all those things, but there your rights stop. No one has the right to stop me writing this book. No one has the right to stop it being published, or sold, or bought, or read.

The security services are alarmed. Every nation that does research into fundamental physics — what we call experimental theology — is turning to its scientists urgently to discover what's going on. Because they know that something is happening. And they suspect it has to do with other worlds.