“The Long Sleep” is episode twenty-six of season one of UFO and the season and series finale.
Colonel Lake enters Straker’s office; a witness to a UFO incident has just come out of her coma after ten years. He doesn’t remember, until being told she was hit by a car. Which Straker was driving.
Straker meets Dr Jackson at the hospital and they talk about the woman, Catherine Frazer, as someone watches them enter her room. She remembers Straker. Jackson calms her down and then speaks to Straker; she’s mostly accepted that Straker wasn’t responsible for the accident. Catherine doesn’t know that she’s been in a coma for ten years or that her parents are dead. Straker is her only link to the past.
The watcher is eavesdropping as Straker speaks to Catherine. He explains his job and she remembers the UFO; she saw it from the farmhouse where she and Tim were sleeping. She remembers Tim falling from the roof. Catherine ran away from home and doesn’t remember the farmhouse’s location. She met Tim and he suggested they go to the country, to a farmhouse he knew of. That night, Tim takes some drugs and convinces Catherine to do the same. They are high when a UFO lands and see it and two aliens. The aliens were burying something in the floor and Tim took a cylinder. They all ended up on the roof and Tim jumped. She was knocked out by the aliens and doesn’t remember what she did with the mechanism, or the location of the farmhouse. When she woke, she saw Tim, then the aliens taking this body, and she took the mechanism and left the farmhouse.
Straker is concerned because the believes the thing the aliens were burying was a bomb and the mechanism stolen was the detonator, which is why it hasn’t gone off. They need to find the mechanism, and the aliens are looking for it too.
There was no second season made, but some of the work planned for that was used on Space: 1999.