The Stranger (Colin Baker) arrives on Earth with no memory of who he is or why he's there. However, two men on a secret mission seem to know his identity and the owner of a local bar/club seems to be hiding a secret in an upstairs room. Unsure of whom to trust or even believe, The Stranger must try and unravel the threads of his mysterious past...a past he may not want to remember.

In a top-secret UNIT warehouse Dr Sally Arnold is studying a Nestene energy unit with little success. Until she subjects it to cosmic signals that activate it and it awakens several dormant Autons stored in the facility.

The Airzone Solution takes place in a future Britain where pollution has reached a point where the populace must often wear filtration masks when they venture outside. AirZone, a powerful corporation, signs a lucrative deal with the government to deal with the problem. The public is told that AirZone plans to build giant filtration plants to clean the atmosphere, but environmentalists are skeptical, especially when people begin dying and disappearing around AirZone facilities.