Guest Stars John Newman as Spencer Bill Matthews as Davis Geoffrey Palmer as Masters Pat Gorman as Silurian Pat Gorman as Silurian Scientist Paul Darrow as Captain Hawkins Thomasine Heiner as Miss Dawson John Churchill as Silurian Nigel Johns as Young Silurian Gordon Richardson as Squire Simon Cain as Silurian Paul Barton as Silurian Richard Steele as Sergeant Hart Roy Branigan as Roberts David Pollitt as Private Wright Harry Swift as Private Robins Dave Carter as Silurian Dave Carter as Old Silurian Brendan Barry as Hospital Doctor Peter Miles as Dr. Lawrence Nancie Jackson as Doris Squire Norman Jones as Major Baker Ian Conningham as Dr. Meredith Alan Mason as Corporal Nutting Peter Halliday as Silurian Voices Fulton Mackay as Dr. Quinn Ian Talbot as Travis Keith Ashley as Technician Joan Harsant as Technician Bernard Barnsley as UNIT Soldier Jim Delaney as UNIT Soldier Brian Nolan as UNIT Soldier
