Synopsis
Synopsis Mortally wounded by the Spider Queen on Metebilis 3, the Doctor is forced to regenerate. His recuperation is cut short as UNIT investigates a spate of robberies involving components for a top-secret disintegrator gun. The culprit is quickly identified as a highly sophisticated robot built by Professor Kettlewell, which is being ordered to act against its Prime Directive. (Episodes 1-4, 98 mins)