Richard Bromley receives a visit from Alex Coulsdon, who turns out to be an old friend of John Collier's from Chorley, and offers to become Richard's new housekeeper. Richard manages to spill a large consignment of honey all over the road, causing traffic chaos. Tony and Dudley get their van stuck in the honey while they're on their way to an urgent meeting with their boss, Ken Ewing. They make their way over by train and are given a severe reprimand for delivering Mr West's vacuum cleaner to the Enhams, while apparently under the influence of alcohol. He tells them that Mr West has threatened to sue the company for the shock to his system after seeing Syd Enham doing something unspeakable with it. To try to make amends, Dudley offers to take Ken to a football match, and is offered some work in a cafe.
Meanwhile, DS Worth Roaden is called in to investigate the honey spillage. He takes some details and helps Richard to clear things up. Richard invites him to dinner, but DS Roaden has to go and speak to the Enhams first to investigate the possible theft of Mr West's vacuum cleaner. The Enhams turn out to be a mad dysfunctional family with a domineering mother, Beck, and a wayward uncontrollable daughter, Hillary, as well as the rather meek father Tom and his son Syd, whose rat-eating habit is also shared by his mother and sister. DS Roaden tries to get some details but it's all too much for him. As a result, Tom realizes that the vacuum cleaner was not in fact intended for them, and arranges for the delivery company to come and pick it up. They're rather incompetent and say they can't do so for a month.
There's a brief interlude set in America where Richard's former housekeeper Ava tells her new husband Walt about her student days as a comedy performer. Then DS Worth Roaden arrives at Richard's house for his dinner appointment. They get into conversation and Alex reminisces about holidays in Cornwall with John Collier.
Dudley returns from the football match, having failed to persuade Ken Ewing to let him and Tony off the hook. To keep their jobs, they have to go back to Leyburn Avenue and take the Dyson vacuum cleaner from the Enhams back to Mr West, but neither of them can face it. Tony accosts Bob, a hard-up colleague, and offers to pay him off if he'll do the job for them. Bob accepts.
Tony then sees Don, who has just joined the company under the alias "Rick Mansworth", and warns him that company staff aren't usually paid like that. Bob phones the Enhams and is surprised to hear from Hillary, who is alone in the house, and who Dudley and Tony have never met. She waffles on inanely but Bob eventually persuades her to put the vacuum cleaner in the box and leave it for him. Unknown to him, she seizes on the inferior Orwood model, left by Mr West, and puts that in the box instead.
Bob races off but is involved in a road accident with a Mr R.T. Holt. He doesn't have time to sort things out with Mr Holt and presses on to the Enhams' house, where he picks up the vacuum cleaner from Hillary, not realizing it's the wrong one. Mr West is away and Bob delivers the cleaner to a Mr R. Wood, who is minding the house for him.
Meanwhile, Richard and Worth are discussing politics when Alex comes in and serves the dinner. Richard and Alex have an animated discussion about tomorrow's meal, then Worth suggests they all go out for a drink. Richard recommends a country pub, 'Ye Olde Whyte Leafe'. On the way they stop to buy some potatoes and Worth starts flirting with Alex in exactly the same way that Walt did with Ava. Richard is terrified of losing another housekeeper and tries to persuade Alex to stay.
Bob comes back from Leyburn Avenue and tells Tony what has happened. Tony is rather worried and phones the Enhams, speaking to Hillary for the first time. He immediately realizes that Bob has picked up the wrong vacuum cleaner and tells Dudley they've got to get to Leyburn Avenue as soon as possible. Bob asks for his money, but Tony puts him off.
Dudley and Tony race down to Leyburn Avenue. Just before they get to the Enhams' house, Mr West returns from his break and sees what he thinks is his vacuum cleaner. Dudley and Tony pick up the right vacuum cleaner from Hillary and sprint along to Mr West's house, but arrive just too late. He threatens to sue the company and then collapses on the floor.
Richard, Alex and Worth are still in the pub, and attract the attention of Fred Monton-Green, but don't notice him. Back at the Enhams' house, Beck returns from junction spotting and attempts to cook dinner for an imminent visit from Sister Mary Le Bone.
At Mr West's house, Dudley phones for an ambulance and tells Tony to swap the vacuum cleaners round. As Tony finishes, Dr Ayton arrives at the house and diagnoses heatstroke. He stays with Mr West and lets Dudley and Tony go on their way.
Richard and Worth are getting increasingly drunk, and Fred offers to drive them home. Worth attempts to seduce Alex, and reveals his ambitions to be a songwriter.
Tony and Dudley arrive back at the depot and are summoned by Ken Ewing, who tells them that Dr Ayton has phoned on behalf on Mr West, who has apparently forgotten the entire incident, and wants to thank them for the new vacuum cleaner. They are delighted but realize they still owe Bob for his favour, but don't want to pay him. Dudley presents him with the cheap vacuum cleaner instead.
Richard wakes up at home with a hangover, but Alex is nowhere to be seen. It seems that she's gone off with Worth. He is about to resign himself to looking after his own house again, when he receives a visit from someone calling herself Crystal, who has been informed that Richard is looking for a new housekeeper.