Guest Stars Nicholas Courtney as Alistair Gordon Lethbridge-Stewart Peter Halliday as Packer Kevin Stoney as Tobias Vaughn Sally Faulkner as Isobel Robert Sidaway as Captain Turner Dominic Allan as Policeman James Thornhill as Sergeant Walters Ian Fairbairn as Gregory Edward Dentith as Major-General Rutlidge Sheila Dunn as Phone Operator Peter Thompson as Workman Uncredited John Levene as Benton