A time gate... A team of teen scientists... A desperate fight to survive....
A rock slide at a fossil site uncovers a portal through time. Park Ranger Hannah and a team of fossil hunters are caught in it and whisked back to an era when giant predator mammals roamed the earth. Before they can find their way home, they must survive the Dawn of Mammals.
In book 4's adventure, The Miocene epoch places them nearer to home, but can they make it back without a lost team member's knowledge? After Hannah abdicates as leader, relationships shift. Ancient canids hunting in a pack bring down another human. Who will survive this epoch, and who will fall?