Book excerpt: What's it like to see your friend transformed into a raven before your very eyes, and to know it's your turn next? How does it feel to morph into a manta ray or slide into the body of a snake? This is what happens to Miranda, Semi and Arnie, three friends who are the sole survivors of a plane crash. They find themselves on a tropical island of azure waters and white sands. But beyond the palm-fringed beaches lies the hospital run by the sinister Dr Franklin, and the three teenagers are about to become his next patients. Perfect candidates for his experiments in genetic engineering. . . A horrifying, fascinating story that is Ann Halam's most unusual and challenging novel so far.