Tunnels - the book.

First there was Tunnels, the book that started it all, then came Deeper, Freefall, Closer and Spiral, and now the last instalment, Terminal, has been released in the UK and will be out in the US in October. Published in more than forty languages, the books have made three appearances on the New York Times Bestseller List, and been bestsellers in more than fifteen countries. Relativity Media of the US purchased the rights to make the Tunnels movie, with production expected to start soon under the newly appointed director, Mikael Hafstrom.