The Master offers to help the colonists in exchange for information on the Primitive city and forces the Doctor to act as a guide by taking Jo hostage.
Quest roles:
John Ringham(Ashe), Bernard Kay(Caldwell), Pat Gorman(Soldier), Roger Delgado(The Master), Helen Worth(Mary Ashe), Morris Perry(Dent), Tony Caunter(Jackson), Nicholas Pennell(Winton)