Sian is midway into her investigation, and with corroborating eyewitness accounts of cigar-shaped crafts building and now strange orbs of light in the sky that left people terrified, she's desperate for logical explanations. Multiple people claimed to have seen a pulsating light around Stack Rocks, so she takes a boat out, determined to see the site for herself. Sian turns to science — can it deliver an explanation for the orbs of light? She heads to Oxford University, where astrophysicist Dr Becky Smethurst demonstrates how plasma can be created by nature. For a few moments, the strange phenomena feel explained, but reality sets in. It doesn't explain the schoolboys seeing the same object in the sky or hotelier Rosa's claims of strange figures. Sian is forced to relook at the evidence. Despite her scepticism, recurring details in the accounts are becoming harder to ignore — eyewitnesses with no connection to each other all reporting radio interference and cigar-shaped craft. What did original investigator Randall make of these connections? Returning to the archive, Sian finds a newspaper clipping which reveals Randall became so disturbed by what he found that he quit the case, issuing a warning to anyone following in his footsteps. Sian is shaken. Local author Neil Spring, who has researched the case extensively, warns Sian that he's heard stories of people who have investigated the case receiving strange visits from mysterious figures claiming to be from the government, telling them to stop. And, he warns her, this case is far bigger than Sian realises — it's not just about a seaside village — it involved hundreds of eyewitnesses spread out across south and west Wales. Sixty miles down the coast, in Swansea, she meets Natalie, who is convinced that, as a 13-year old, she saw an angular-shaped UFO hovering over her house. The next day, she found a lump on her head. Sian is extremely sceptical — it's too outlandish to believe. But then she finds another local who said he saw that craft too on the same night. Needing answers, Sian heads to the National Archives, where she discovers official government documents that have only recently been declassified. She's speechless to discover pages of reports of other witnesses reporting a strange, triangular-shaped UFO — exactly as Natalie and the neighbour described — on the same night. The government knew about this sighting. Why did they keep these documents classified? And what did these people see?