America, 1958. The Doctor makes a new friend, Cassie, who reveals that anyone approaching the top secret Dreamland army base goes missing.  The Doctor discovers an alien army hatching beneath the New Mexico desert, while inside Dreamland, survivors of an extraterrestrial war possess a weapon powerful enough to destroy earth.

The Doctor, Cassie and Jimmy escape to Solitude where the mystery of the Viperox is revealed.

The Doctor meets Jimmy's grandfather, Night Eagle, and discovers the true story about the Gray aliens.

Colonel Stark and Lord Azlok reveal their secret behind the alliance between the U.S. Army and the Viperox.

While the Doctor and Saruba try to save the life of Rivesh, Cassie and Jimmy search for the TARDIS in the midst of a Viperox invasion.

With the Viperox invasion in full force, the Doctor needs the help of Rivesh Mantilax to activate the genetic device.