He froze. It was the girl's voice again. The one he'd heard when the pain had struck. Clear and urgent, deep inside his head.

That click was a Heckler and Koch MP7 personal defence weapon. It fires 950 armour piercing rounds per minute. The sound you heard was the safety catch coming off.

No! It was talking rubbish. Mum and dad were outside, they'd come back for him. There was no killer with a machine gun behind his bedroom door. How could there be?

The voice in his head was a stupid figment of his imagination. It was just stress, after that terrible pain. He could ignore it. All he had to do was open the door. Mum and dad would be there, smiling at him.

Davy, open that door and you are dead.

He doesn't know it yet, but fourteen-year-old Davy Taylor is about to have the worst day of his life.

With a journalist for a father and a scientist mother, family life has always been nomadic: France, South America and now, London. Coming home from school, he collapses in the street. More pain than he'd ever thought possible... a brain haemorrhage? Is he dying? He staggers home. Surely his parents can help? But they're gone. The flat's empty. He's alone.

And then the voice in his head starts talking.

Davy finds himself facing a powerful underground group who have lived for hundreds of years—and want to see him dead. The future of human existence is in the balance...

About the Author

Brian Clegg is an author of popular science books, including The God Effect, A Brief History of Infinity, How to Build a Time Machine and Inflight Science. He has written for many publications from The Wall Street Journal and the Times to Playboy and Nature. He lives in Wiltshire, England with his wife, twin daughters and golden retriever.