A Naval vessel shoots down a UFO in the Atlantic, but the Admiralty rejects further investigation into the incident. Straker suspects a cover up and wants to know why, so Foster courts Admiral Sheringham's secretary, Sarah Bosanquet. What they discover could mean the end of all life on Earth...

Foster is abducted by aliens from a health spa and is being taken out into space, presumably back to the alien homeworld. However, the UFO was damaged and returns to the moon, crashing there. While the Moonbase personnel try to free Foster of the alien environmental suit, Foster wakes up in the steam room at the health spa. The episode begs explanation for how Foster dreamed in such orderly detail, including Carlin missing a shot and Straker angry at the missed shot, and Dr. Jackson's off-line comments to Straker before they go onto a visual link to Moonbase to guide them through removal of Foster's alien helmet.