The year is 3149. Extensive genetic engineering is commonplace resulting in widespread human variation. Humankind has reached the stars and colonised hundreds of planets thanks to two main technological breakthroughs; anti-gravity and faster than light propulsion known as the Slipdrive. The Slipdrive enables ships to travel above normal space, slipping into another dimension known as Nospace and shortening voyage time between stars from years to weeks. Unfortunately, someone or something, got there earlier: the Shiva. Previous attempts to contact these creatures has resulted in but one outcome. Death. Felix Teppitt, a brilliant young physicist, has helped to develop a revolutionary new form of space drive known as the Overdrive. The Overdrive will enable ships to travel in a dimension completely different from Nospace where no hostile life forms exist - in half the time. When he disappears, his two friends set off on a desperate journey that will determine the fate of the galaxy.