In the near future, the synthesization of dark matter makes time travel a reality. Dan Webber and his son guide wealthy hunters 100 million years back in time where Tyrannosaurs rule and Velociraptors scavenge. New understandings of physics alleviate the once-honored fear of altering the future by new actions committed in the past. But when an anomaly interferes with the time machine's programming, Dan and the others find themselves in a life-threatening...