After the TARDIS makes a crash landing on the Earth of another universe, Rose discovers her father is alive and rich, Mickey encounters his alternative self, and the Tenth Doctor learns one of his oldest and deadliest foes is about to be reborn.

The plans of John Lumic to convert the world into Cybermen are now in full force. The Tenth Doctor, Rose, Mickey and the Preachers must find a way to stop him from enforcing his "ultimate upgrade."

The TARDIS brings its crew to a quarantine facility for victims of an alien plague. When Amy is trapped, Rory must rescue her from the facility's doctors but learns something surprising about his wife.