Simon and Samantha return from holiday to find that Maddie has married at last and moved out, leaving her sister Isobel as her replacement. However, Isobel isn't just clumsy but a terrible cook and Simon considers sacking her but Samantha gets him to relent and he gives Isobel a month to come up to scratch.
Samantha wants to know about her late mother, but all Simon will say is that she was faultless beyond using his toothbrush. She seeks Nell and Derek for more but Simon has primed them not to mention the mysterious Harry.
Simon and Derek are unimpressed by potential client Mervyn Drover, an alcoholic who will offer a contract if they put his girlfriend on payroll. Soon after, they learn that Nell, doing crossing duty at Samantha's school, has been knocked down by a car — driven by Drover.
After quarrelling with his wife Muriel, Derek moves in with the Harraps but the men decide not to tell Samantha as they think that she's too young to understand. However, Samantha teams up with Derek's daughter Annabelle to reunite the warring couple.
Simon is out to renew the firm's valuable contract with Britannia Biscuits and shows its elegant female marketing director, Portland McIntyre, a video of its achievements. Unfortunately, a porn film has been substituted.
Whilst Simon needs a bank loan, Fergus needs to impress girlfriend Anthea and persuades Derek to pretend that Fergus is his boss, using the Eyecatchers office. Alas, Anthea, unimpressed by Derek, wants him sacked.
Simon's latest date expresses frustration at her sister and her family staying with her, which gives Simon the impression that she's not child-friendly. So he pretends Samantha doesn't exist.
After being beaten at squash by Simon, Derek bets Muriel's car against Fergus' that Simon will beat Fergus at squash – which he does. The bet is won by Derek, but is on again when Fergus's niece and Samantha audition for the same part.
When Simon learns that his new client Mr Brocklebank is an old flame of Nell's from four decades earlier, Samantha resolves to reunite them. However, Mr Brocklebank is now married.
Samantha and her new friend Gemma plot to get Simon paired off with Gemma's mother, Laura.
While Simon is in hospital with appendicitis, the VAT man comes to inspect the firm's books.
Simon finds a young woman named Jennifer drunk in the street. He brings her home to sleep it off and gallantly gives her his bed while he sleeps on the sofa. Next day, however, she tells Samantha that she is Simon's betrothed and they are going to get married. Among the celebrants is Jerry, Jennifer's boyfriend, who is out to do Simon harm.
A client promises the Harraps a holiday in Greece in exchange for making a video but on arrival at the airport they discover the tickets are worthless as the company has gone bust. Fortunately Nell's friend Pinky saw this coming and made sure the company never got the tapes as well as providing them all with a holiday in his country cottage.