On the night of January 23, 1974, residents across the Berwyn Mountains in north Wales report a loud bang, a flash of light, and the ground shaking beneath their houses. Some assume it is an earthquake, since a minor tremor is recorded that night, but locals soon add sightings of strange lights and rumors of a crashed object on the mountainside, and the story spreads as Britain's answer to Roswell. This episode of the Britain's Closest Encounters series revisits the incident through the people who were there that night and the investigators who came after them, weighing the earthquake explanation against a meteor strike, a military test gone wrong, and the UFO theory that gave the case its lasting reputation. No official account has ever fully closed the file. The film lays out what is actually documented, a seismic reading, scattered eyewitness reports, and decades of competing claims, without settling on a single verdict.