© Bentley Productions/Mark Bourdillon


Forest ranger Felicity Ward is driving at night when she is blinded by a searing light from an unidentified flying object. The following morning her car is found abandoned at the roadside.


Barnaby tells Sarah that he doesn't want a party for his birthday before being called to the crime scene where a black pod containing Felicity's body is discovered. The village of Cooper Hill is buzzing with news of the 'UFO'. Hoteliers Victor and Nadine Campbell and daughter Orla and tour operation Abigail Tonev and her garage owning son, Nathan rely on the stream of Ufologists for their businesses. Barnaby and Nelson visit Felicity's mother Valerie and fiance Brogan, who explain that the RAF base is run by her estranged father, Group Captain Ford, and reveal that Felicity was going to confront a Ufologist Carter Faulkner, about his illegal campsite. At the RAF base Barnaby meets Sgt. Ali, who claims that the base has picked up no 'UFO' activity, and Ford, who claims to have been in his quarters all night. Nelson meets Faulkner's son Dillon at the campsite, who lies that his father Faulkner is out and Kam admits to being completely baffled by the gloop - it's alien to her.


A ring discovered around Felicity's neck provides a new lead. Brogan denies recognising it, as do Valerie and Ford, leading Barnaby to suspect a secret lover. Nelson learns that Faulkner is a well known UFO spotter following his alleged alien encounter in 1984. When Barnaby returns home he overhears Sarah making plans for a surprise meal on the phone, and in the woods at night Abigail is 'buzzed' by the mysterious UFO. The next day Kam identifies the gloop as an experimental prototype and reveals she found distinctive catkins on Felicity's body. Nelson discovers the ring is German enabling Barnaby to identify Ali as Felicity's secret lover. Ali admits to the affair and alludes to radar readings about the UFO. When evidence places Victor in Felicity's van he is forced to admit he was keeping an eye on her for Ford, his former boss, and that Ford knew about her affair with Ali. That night the body of Ali is found hanging in a pod.


Brogan's threatening of Ali makes him a suspect, but Kam makes a breakthrough: the catkins were also present on Ali's body. It leads them to Hunter's Clearing, where Nelson pursues a mysterious figure and Kam finds a shallow grave. At the base Ford admits to anomolous readings but suggests it's a prank. Kam tells them that the grave was recently excavated. Back at the clearing Barnaby and Nelson discover underground tunnels linked to the RAF base and the mysterious symbol. Barnaby realises he mis-understood Sarah's earlier restaurant booking (it was for a colleague) whilst Nelson deduces that the grave belonged to Eric Tonev, Abigail's husband, who went missing in 1984. A shocked Nathan reveals that Tonev worked at the base, but Victor's adamant that Tonev was a traitor. That night Faulkner watches the UFO crash....before being murdered.


Barnaby digs into Eric Tonev's background and Abigail reveals Tonev worked on a secret project, Omega-4, whilst Nelson unmasks Orla and Dillon as the UFO hoaxers. Nadine reveals that Ford wanted rid of Eric because he was sleeping with Veronica. It's a big breakthrough and Barnaby and Nelson go to the Tonevs where they find Ford, who has come to help Abigail, and the missing remains of Eric Tonev. But who is responsible for his death? Can Barnaby and Nelson stop the killer striking again?