Prehistoric Animals Break into US Parks Book 3

In this adventure, Markie and the team are heading for California. In the San Bernardino National Forest, there is trouble brewing. Saber-toothed tigers and giant short-faced bears are creating great havoc. They are really dangerous and put the team in extreme situations. However, things are not what they seem. An unseen figure is watching the team's movements and is doing whatever it can to hinder their efforts in succeeding in this mission. What could possibly happen?