The Exodus Towers

Hough's second Dire Earth Cycle SF thriller (following The Darwin Elevator) more than lives up to the promise of its predecessor. The alien Builders inflicted a deadly plague on Earth, along with technology%E2%80%94space elevators and movable towers%E2%80%94that provide immunity from the virus. Now a new human colony faces a number of crises, and looming above them all is the knowledge that the mysterious Builders are scheduled to return within two years. Dashing scavenger Skyler Luiken and beautiful scientist Tania Sharma race against the clock%E2%80%94though clocks are increasingly unreliable%E2%80%94to be ready for the encounter. Events speed up dizzyingly toward the end, and a subplot involving a dangerous cult is overly long. However, Hough knows how to hook his readers with action, intrigue, and sympathetic characters, and fans of the first book will be enthralled. (Sept.)