Having finished work on Time Sphere II, Rip Hunter and Jeff Smith do a test run back to the mesozoic era. Meanwhile, in the present day, crooks force Bonnie Baxter and her brother Corky to take them to Rip and Jeff in Time Sphere I. Meeting in the past, the crooks have the drop on Rip and crew, until battling dinosaurs separate the good guys from the bad. But when the heroes get back to their Time Sphere, they find it's gone missing.

Having finished work on Time Sphere II, Rip Hunter and Jeff Smith do a test run back to the mesozoic era. Meanwhile, in the present day, crooks force Bonnie Baxter and her brother Corky to take them to Rip and Jeff in Time Sphere I. Meeting in the past, the crooks have the drop on Rip and crew, until battling dinosaurs separate the good guys from the bad. But when the heroes get back to their Time Sphere, they find it's gone missing.