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