Spanners: The Fountain of Youth

Most people live out their lives in one fixed order, from birth to old age, but a rare group called spanners does not. Their lifespans run in odd patterns: some age backward, some last only half a year, and some never die at all. Hundreds of kinds exist, each with its own span and its own set of abilities. A few manage to blend into ordinary society, while most keep to the shadows. Some are dangerous, and Adam Parr, a detective who is himself thousands of years old, works to keep the worst of them in check, partnering with a short-lived spanner called Mayfly. Their task gets harder when an old enemy of Adam's discovers the most potent and feared spanner ever known. Adam and Mayfly must track her down before she unlocks her full strength and threatens the entire world.