Caitlin Decter is young, pretty, feisty, a genius at math—and blind. But, she can surf the Net with the best of them, following its complex paths in her mind. When a Japanese researcher develops a new signal-processing implant that might give her sight, she jumps at the chance, flying to Tokyo for the operation. But the visual cortex in Caitlin's brain has long since adapted to allow her to navigate online. When the implant is activated, instead of seeing reality, she sees the landscape of the World Wide Web spreading out around her in a riot of colours and shapes. While exploring this amazing realm, she discovers something—some other —lurking in the background. And it's getting smarter …