Where Was I?

Keith Amery is overworked and stressed, and he disappears without telling his family where he is going. He buys camping equipment and heads for the moors, where he sees a helicopter landing beside a tractor and a cement mixer. The helicopter comes at him, he falls and hits his head, and, still pursued, he jumps into a passing farmer's van. He gets home and tells his wife he cannot remember anything. One of the doctors who treated Eddie at Fordingdale brings Keith's wife to the station, and she explains her husband's condition.

The investigation is a reconstruction of a journey from material evidence, and it is the show's most methodical piece of detection. Two Australians take Amery's tent to a camping equipment shop looking for the name of its owner. Eddie visits the same shop and gets nowhere, then collects Amery's abandoned car from a car park, and sitting in it Amery remembers a blue pick-up truck loaded with milk. Eddie gives Amery's clothing to Erica, who passes the garments to police forensic scientists. A woman visits an inmate at a prison near the moors and tells him everything is going to plan. She then passes herself off to Don as a representative of a small Australian radio station that wants a private ear of its own, and Eddie is told, to his annoyance, to let her follow him around for a few days. She records their conversations on a dictaphone. The forensics report places the mud on Amery's boots on the moors, finds soot on the clothes and a ticket suggesting a steam train. At the preservation society Amery belonged to, Eddie and the woman travel on an old locomotive, and the inspector tells Eddie where Amery got off. Walking the moors, Eddie finds the site with the tractor and the cement mixer.

Back at the station, Amery is kidnapped by the Australian before Eddie can get him onto the train. Sonia then finds the dictaphone the woman has been using, can find no trace of the Australian station she claims to work for, and describes the sand she found in the beach buggy the woman drove. Eddie drives to the nearest beach and watches three people leave the lifeguard's hut in a Range Rover. Inside he finds Amery tied and gagged, and gets him out before a bomb wired to the telephone goes off. They drive to the moors, where at the deserted building site Amery remembers he camped there and mentions the helicopter. A prison bus arrives: prisoners from a nearby jail use the site for outdoor work, and among them is the man the woman visited. A helicopter comes in, and Eddie works out what Amery saw: a rehearsal for a prison escape, staged on the moors to be repeated when the bus arrived. Amery had a front-row view of the practice run, and the people running it could not risk his memory coming back. The prisoner runs for the helicopter and Eddie tackles him and brings him down. The helicopter gets away, but Don tells Eddie its occupants had to land because of the weather.

The structure is the achievement: the audience knows more than Eddie and less than the villains, and the episode converts a set of objects, boots, jacket, ticket, tent, car, into a route across the moors. It is the closest the show came to a 1960s adventure format. Hilary Ryan's impostor is the best-written guest: she arrives as a nuisance, is believed by Don, is exposed by Sonia and turns out to be the operation's organiser rather than its decoy.

The weak points are the twist, which the fan commentary concedes is rather obvious in retrospect, and two coincidences the episode cannot do without: Amery escaping on a passing van, and the prison work party arriving at the exact site at the exact moment. Nine of the ten episodes kept to a domestic or commercial setting; this one needs a helicopter, a steam train and a prison bus to work. It drew 9.4 million viewers, the lowest of the run.