Sci-Fi series broadcast by the BBC in two seasons, 1984/85. It was based on a trilogy of books by John Christoper.
The third book was never filmed, much to the dismay of its many fans. The Tripods is a post-apocalyptic story in which humanity has been conquered and enslaved by "The Tripods", unseen alien entities who travel about in 100 foot tall, three-legged walking machines (humans are unsophisticated and believe the walking machines themselves to be their living overlords). Human society is largely pre-industrial and farm based, with few habitations larger than villages, and what little industry exists is conducted under the watchful presence of the tripods. Lifestyle is reminiscent of the Middle Ages, but artifacts from later ages are still used, giving individuals and homes an anachronistic appearance.
Earth's greatly reduced population is controlled from the age of 14 by implants called "caps", which suppress curiosity and creativity and leave the recipient placid and docile, incapable of dissent.
In the first series the main characters are two young boys, Will and Henry Parker, who have rebelled against the idea of capping and travel from southern England through France to Switzerland, picking up a third companion, 'Beanpole', on the way. They are travelling to 'The White Mountains' (the title of the first book) to join a group of uncapped known as The Freemen. The second series, based on 'The City of Gold and Lead', sees Will and Beanpole along with a new character, Fritz Eger, journeying to compete in 'The Summer Games' in order to gain entry to the Tripods city and gain information to help the Freemen overthrow the Tripods, as the champions are chosen to serve the Tripods there. Only Will and Fritz make it through and the series centres around the two.
Here we find out that the walking machines are merely vehicles for the alien 'Masters' and see the actual beings themselves in their City. Their appearance is striking, being a departure from humanoid looking, a rarity for its time.
Although a script was written for the third series, it never made it into production. Different reasons have been raised, the most likely being high production costs and a move against TV Science Fiction. Whatever the reason, it left many fans extremely disappointed.