- Author: Chris Ryan
- Format: Paperback
- Publisher: Random House Children's Publishers UK
- Published: 05 February 2009
- ISBN: 9781862302815
When Ben Tracey sets out with his cousin to spot hen harriers - a protected bird of prey - he doesn't expect to stumble upon a secret operation. But renegade researchers are using a military base near the birds' nest site to develop Project Vortex: a project concerned with a top secret, utterly illegal and highly lethal weapon! As the clock ticks down, Ben and Annie are in a race against time to prevent disaster. But their enemies are determined to stop them and they will go to any lengths...