Lou is different to 'normal' people. He interacts with the world in a way they do not understand. He might not see the things they see, however, but he also sees many things they do not. Lou is autistic. One of his skills is an ability to find patterns in data: extraordinary, complex, beautiful patterns that not even the most powerful computers can comprehend. The company he works for has made considerable sums of money from Lou's work.

But now they want Lou to change - to become 'normal' like themselves. And he must face the greatest challenge of his life. To understand the speed of dark.

2004 Nebula Award