Arthur is taken aback when he finds that Terry has emigrated to Australia without telling him, leaving only his old Capri behind. He is anxious to find a new minder and this is where his young nephew Ray comes in. Ray is not a fighter like Terry but he can speak French and this comes in mighty handy when Arthur seeks to expand his business interests onto the Continent, only to find that he is involved with drug smugglers.
Arthur buys a consignment of wine from dodgy Herbie, which he intends to sell to the local corner shop. When the wine is impounded Arthur and Ray break into the warehouse to retrieve it but, after a disastrous tasting session, have to put it back - and end up getting locked in for the night.
With a serious cash-flow problem and a newly-erected flag-pole advertising "British is Best" at the car lot, Arthur is suspected of bumping off his wife for the insurance and burying her on the forecourt when she disappears and he cannot account for her. Needless to say she returns, having gone to a health farm, but Arthur is more concerned about the flag-pole than Her Indoors.
Three victims of Arthur's past cons conspire to trick him into buying an East German car, a retired greyhound and a piano. He strives to find buyers for them before business rival Ashley Brown broadcasts his gullibility around the manor - though he is fortunate that Ray is no mean con-artist himself.
Whilst attending Charlie Johnson's wake in Pinner, Arthur attracts the lustful attention of merry widow 'Ron' Johnson but gets so drunk he has no recollection of his conversation with fellow mourner, dodgy Tommy Hambury, which he believes to be important, and takes desperate steps to find him. The police, believing Arthur is trying to take over Charlie's dubious empire, give chase.
Having given up smoking and drinking on doctor's orders an already nervy Arthur is not helped when 'Mad' Benny McLeish, a truculent dissatisfied customer, threatens violence unless he gets a refund. Having been denied police protection, the cowardly Arthur hides at Ray's but when he disappears behind his minder's back to buy his forbidden pleasures, Ray convinces the police that McLeish has abducted him, leading to a punch-up in a pub car park.
Arthur's Yorkshire contact Billy hires Ray to guard Young Sam, his racing pigeon, on the eve of a race whose prize money is worth ten thousand pounds. Due to Arthur's stupidity, Young Sam escapes, requiring Arthur and Ray to 'acquire' a substitute from a station platform. Although Young Sam ultimately returns, matters are complicated when Ray falls for Donna, daughter of a rival pigeon-fancier.
Stuck in his lock-up, due to a faulty alarm system fitted by ex-burglar Ron, when he should be taking his wife out for her birthday, Arthur is arrested as a prowler by a zealous rookie cop. Ron, meanwhile, is robbing warehouses on a list given him by Arthur as potential customers for security alarms and gets Ray nicked when he tries to stop him. For once it is Arthur who has to bail out his minder, rather than the other way around.
A nostalgic Arthur plans to host a number of variety acts at his local pub, including the great ventriloquist Tommy Pickford, now retired. To please the youth market he hires a karaoke machine. Both go down a storm but then the machine, rented to Arthur by the fearsome Gabadini family, is stolen. Ray plays detective to get it back.
Arthur's latest ill-starred venture is Daley's Catering International Cuisine, booking on banquets. Unfortunately for him his chef is wanted by a group of gangsters and goes on the run, leaving Arthur in the lurch as he is about to cater for a policeman's retirement party. Once again the services of the long-suffering Ray are required.
Wealthy Lewis Nelson hires Ray to keep his much younger, gambling-addicted wife Lorna away from the casino he part owns, as she has run up heavy debts. Lorna persuades Arthur to play the roulette wheels on her behalf whilst she is gated and he wins. Whilst collecting bin-bags of used cards from casinos to sell on, Arthur has also picked up a bag of money Lewis intended to steal from the casino to pay Lorna's debts. He decides to return it - in his own fashion.
Arthur buys a coach from the cash-strapped local police to use for sight-seeing tours but it breaks down, so he takes the tourists to the Winchester Club, where they are thrilled to see a genuine old English pub brawl between Arthur's creditors and Ray. After the police buy back the coach, Ray also becomes a hero at the local golf club, ensuring Arthur full membership.
When Ray's van breaks down whilst delivering two hundred video recorders to a client in Limehouse Arthur needs alternative transport - and fast, especially as he learns they were stolen property and psychotic Big Dai wants them back. His answer is to take them by barge, the ancient 'Persephone', a journey which inevitably ends in disaster and some very wet video recorders.