Guest Stars John Newman as Spencer Bill Matthews as Davis Geoffrey Palmer as Masters Dave Carter as Old Silurian 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 Brendan Barry as Hospital Doctor Peter Halliday as Silurian Voices Ian Talbot as Travis Thomasine Heiner as Miss Dawson Fulton Mackay as Dr. Quinn Paul Darrow as Captain Hawkins Peter Miles as Dr. Lawrence Alan Mason as Corporal Nutting Ian Conningham as Dr. Meredith Norman Jones as Major Baker Pat Gorman as Silurian Pat Gorman as Silurian Scientist Nancie Jackson as Doris Squire Keith Ashley as Technician Joan Harsant as Technician Bernard Barnsley as UNIT Soldier Jim Delaney as UNIT Soldier Brian Nolan as UNIT Soldier