The Doctor and UNIT are called in when an underground research centre experiences problems. Nearby the Doctor discovers a group of intelligent reptiles, known as the Silurians.[1]
| No of Episodes[2] | First Broadcast[2] | Writer(s)[2] | Script Editor(s)[2] |
|---|---|---|---|
| Seven | January 31 - March 14, 1970 | Malcolm Hulke | Terrance Dicks |
| Director(s)[2] | Producer(s)[2] | ||
|---|---|---|---|
| Timothy Combe | Barry Letts |
| Episodes[3] | |||
|---|---|---|---|
| Episode One, broadcast January 31, 1970 | Episode Two, broadcast February 7, 1970 | Episode Three, broadcast February 14, 1970 | Episode Four, broadcast February 21, 1970 |
| Episode Five, broadcast February 28, 1970 | Episode Six, broadcast March 7, 1970 | Episode Seven, broadcast March 14, 1970 | |
| Notable Cast[2] | |||
|---|---|---|---|
![]() Doctor Who - Jon Pertwee | ![]() Liz Shaw - Caroline John | ![]() Brigadier Lethbridge-Stewart - Nicholas Courtney | |
| Guest Cast Members[2] | |||
|---|---|---|---|
| Dr Quinn - Fulton Mackay | Dr Lawrence - Peter Miles | Captain Hawkins - Paul Darrow | Masters - Geoffrey Palmer |