Lost in the East End of London, TV repairman Gary Sparrow walks down Ducketts Passage, through a time warp into 1940. In the Royal Oak pub there, without either gasmask or identity papers, he is suspected of being a spy. His eye is drawn by the barmaid Phoebe, but she is a married woman whose husband is away in the war. In the cellar during an air raid he teaches the pub regulars some songs. He also helps Eric, Phoebe's father, who is injured during the raid. But what will he tell his wife Yvonne, when, and if, he gets home?
Ignoring Yvonne's advice, Gary goes for a promotion interview but does not wear a suit. His friend, Ron, hearing Gary's call to a radio phone-in program, is intrigued to know if he really did travel back in time. After another argument with Yvonne, Gary does buy a suit, though not quite what she had in mind. He returns to Duckett's Passage to see if he can go back to 1940, and what he found there.
Gary & Yvonne argue about her preoccupation with her OU degree course and his obsession with WW2. Warning Phoebe that the bombing will start early that evening, Gary takes her to Holborn Underground station to shelter overnight. When they return to the Royal Oak next morning, he is questioned by the police. Back in their Cricklewood home, Yvonne is worried when Gary fails to return from work that evening.
Gary asks Ron, who is a printer, to forge him some 1940s identity papers. Although he dresses for the part, Ron finds that only Gary can go back to 1940. While walking in a cemetery, Phoebe asks Gary to take her back to the 1990s with him. Back in the 1990s, Ron is angry, and Gary drives all the way to Huddersfield, where Yvonne has gone for her OU degree course, worried that Ron has told her about Phoebe.
Wanting to improve their marriage, Yvonne decides to share an interest with Gary. News of an old lady leads Gary to believe he must return once more to 1940. Ron goes to Lithuania to watch an England football match as a cover. Gary is knocked down and comes to in the hospital with Phoebe & PC Deadman by his bedside. With Gary's stay in 1940 extended, Ron decides to tell Yvonne that Gary has been held by the Lithuanian police.
Gary decides to make another visit to 1940, following an ultimatum from Yvonne. Ron forges some 1940s money so that Gary can make a killing on the Stock Exchange. PC Deadman brings news of the King's visit to East London and Gary arranges to visit the London Hospital. Gary takes Phoebe for a meal at the Savoy to say goodbye, and secretly books the Imperial Suite. Phoebe's father, Eric, brings her some important news. Gary gives Yvonne an unexpected present, and she points out someone who looks rather familiar in an old 1940s newsreel.
Gary realises that life in 1941 is not what he expected. The water supply is interrupted by a bomb, and he is put on fire-watching duty. Phoebe is incensed to discover that her relationship with Gary is the subject of gossip. But how can Gary go home to 1995, when he has ""committed suicide"" there?
Gary goes back to 1941 to give a concert in Palmer's Green, but only returns home in the early hours. Wix wants to sign a contract with Gary to publish ""his"" songs, which Phoebe thinks is a good idea. When an air raid occurs, it prevents Gary from playing in Plaistow and from returning as he intended to make his theatrical debut? And what were those pills the doctor has prescribed for Gary's nerves?
Gary gets scared when Yvonne thinks they are going to become parents. When he goes to see Phoebe, she is about to go to Buckinghamshire to visit her orphan cousins. Yvonne arranges to make a weekend visit to her mother. Gary goes with Phoebe to Buckinghamshire, but meets someone else, while Phoebe is attracted to a handsome American airman.
Gary buys a shop for his new business selling World War Two items, and Ron terrifies the protagonist when suggesting he might have influenced the Americans' decisions over Pearl Harbor. Thus to prevent putting a dint in history, back in the 1940s Gary tries convincing a senior American of the Japanese attack.
An unexpected wartime bomb hits Ducketts Passage and blows Gary and his son into to the present. Yvonne returns early from Switzerland, her holistic cosmetics business becoming increasingly successful, and Gary has to explain away the lad's existence when they bump into each other at Ron's. Meanwhile, Gary & Phoebe consider moving to Mayfair, which should be safer, and find they have a famous neighbor.
Gary is moving up the social ladder in both eras, though not smoothly in either. Noël Coward helps Phoebe to cope with living in the West End when she has trouble with the butcher, by showing her how to improve her accent. As Yvonne's business makes her a celebrity, she plans a new house, and is invited to the Woman of the Year awards, which is followed by a party at No 10 Downing Street. Gary and Phoebe get their revenge on the butcher.
Ron signs up with a dating agency. Yvonne makes a date with Gary, but when an unexploded bomb goes off in Ducketts Passage he has a problem. It is so serious that Ron misses his date to come to help. The two sides of Gary's life collide head on, and it appears that now others can travel between the 1940s and the 1990s.
Ron takes advantage of the new ability to use the time gate, and as Gary's supposed commanding officer can do anything he wants. Since Reg has been promoted to a position in Scotland Yard, Ron takes everyone to a West End club to celebrate, but becomes a huge liability for Gary. Unfortunately, Yvonne obtains complimentary tickets to a Chelsea soccer match for the very same evening.
Yvonne continues to travel for Nature Boy Cosmetics. Gary takes Phoebe to the Cafe Royal, where his false wartime identity finally catches up on him, and he is recruited for a secret mission to the Isle of Wight. However, Yvonne also has a special mission for him. When he arrives at his destination in 1943, the Isle of Wight looks remarkably like France.
Gary realises that he is only being used as a ploy to fool the Germans. As the Gestapo closes in on him, he is captured and is to be sent to Berlin for torture, unless he can escape first. Ron stands in for Gary on an errand for Yvonne: meeting a top model, and escorting her to a product launch - but they get sidetracked.
Yvonne is signing copies of her just published autobiography. Meanwhile, Gary finds out from the porter in the 1990s that the owner of his 1940s West End flat is going to be killed in a road accident - what is he to do? He finds a new occupier. Then, racked with guilt, he decides to cause a happier ending.
Phoebe wants to make a career of singing, and she wants Gary to write a new song for her. When he does, he has no idea what he's started. Ron wants Gary to help him with a personal ad. A visitor to the shop surprises Gary when he realises it's his son. Gary wants to go back and change the future for Michael for the better.
Yvonne throws Gary out of their Thameside penthouse apartment, which makes Gary edgy, which in turn makes Phoebe suspicious that there's someone else in his life. Ron has new girlfriend, Flic, who is so classy she's out of his league, and he is desperate to impress her, but Gary is more concerned about getting back with Yvonne.
Gary has to think fast when both his wives decide it's time to move to California. Phoebe's tenancy of the Royal Oak is up, and she wants to start a new life away from the shortages of Britain, but Gary persuades her to open a night club, The Blue Door, instead. Yvonne wants to be near the expansion of her Nature Boy cosmetics into the US market, but Gary convinces her to stay with him in London. Reg retires from the police force, but his leaving party is not a success, though he does he another job immediately, as a security guard at Gary's Mayfair apartment block.
Yvonne sells Nature Boy cosmetics for a multi-million sum. Gary travels back through the time gate in Ducketts Passage, arriving on a foggy night, where things don't look quite usual for the 1940s. At the Royal Oak, he finds it's the 1880s, hough the policeman and a music-hall singer look strangely familiar. He is accused of being Jack the Ripper when two murders occur close by on the two nights he's there. While escaping the mob, he meets the real Ripper...
A Short BBC interview with Nicolas Lyndhurst on the set of Goodnight Sweetheart in Nov 1993