On a barren asteroid, the once-mighty Haddron Empire is on the brink of collapse, torn apart by civil war. The one man who might have saved it languishes in prison, his enemies planning his death and his friends plotting his escape.The Second Doctor arrives as the last act of this deadly drama is being played out - and with both terrifying killers and cunning traitors to defeat, the future hangs in the balance. An adventure featuring the Second Doctor as played by Patrick Troughton and his companions Jamie and Victoria