As the newly-regenerated Doctor arrives on Earth, so does the Nestene too.
Quest roles:
Nicholas Courtney(Brig. Lethbridge-Stewart), Hugh Burden(Channing), Talfryn Thomas(Dave), John Breslin(Captain Munro), Antony Webb(Dr. Henderson), Helen Dorward(Nurse), George Lee(Farmworker), Tessa Shaw(UNIT Officer), Ellis Jones(Technician), Allan Mitchell(Wagstaffe), Prentis Hancock(Salamar), Neil Wilson(Sam Seeley)