In the last years of Queen Victoria's reign, Ned, a middle-class schoolboy whose parents are working abroad, spends his Summer holiday in the Bedfordshire countryside with his great-uncle Silas. Silas is sixty, but very hearty and still attractive to women. He does odd jobs and poaches on the sly, to the horror of his long-suffering housekeeper Mrs. Betts. His son Abel is getting married, and, at the wedding reception, Silas recalls his own happy times with his late wife by singing her favourite song with his new daughter-in-law.
Silas takes Ned to decorate the Railway Hotel and is appalled to find that the landlord, once a jolly man, has become a dour, strict tee-totaller, refusing to serve alcohol to his guests. Queenie, his put-upon wife, takes her share of the profits from the hotel safe, using them to have a happy, platonic day at the sea-side with Silas. On her return she vows that changes will be made, starting with the sale of alcohol.
On his way to see his solicitor to make a will Silas makes a detour to visit Mrs. Gadsby, a feisty, attractive middle-aged widow. Whilst Ned is sent into the garden to pick fruit, she and Silas share some afternoon delight but she gives him good advice as to changing his will to Ned's benefit.
Whilst digging a grave in the local churchyard Silas meets the aristocratic Lady Sylvia, who, unknown to herself is terminally ill. She is outraged to see Silas drinking in the graveyard but when he tells her it is herbal tea and she takes some herself she becomes more friendly. Indeed she ultimately demands a very saucy favour from Silas to stop her from pressing charges when he is caught poaching on her land.
Silas agrees to fight a much younger and fitter boxer known as the Gorilla, in a fairground side-show and plans to weaken his opponent by giving him a diet which will debilitate him. However it fails to work and Mrs. Betts is forced to take drastic action to save Silas from a good hiding.
All is revealed when Silas takes a bath and tells Ned how years earlier, when he was a teenager, he was swimming nude in the river and a girl stole his clothes. He had to bare everything in order to chase her and regain his trousers and says that, to this day, he has no idea who she was. Mrs. Betts does though.
Silas's nose is put out of joint by the visit of cousin Cosmo, who thrills Ned with his stories of foreign travel and charms Mrs. Betts by flirting with her. Seeking attention, he agrees to pose for Hermione, a sculptress, but she ends up revealing more than she should of herself, which causes trouble with her boyfriend.
Silas takes his boar to mate with the sow belonging to the village bobby. Unfortunately Silas himself gets rather too matey with Connie, the policeman's ample wife, and Ned has to help him avert a scandal.
Silas gets work helping with the harvest at the farm owned by Pamela Farrell. He takes pity on Shandy Lil, the put-upon serving girl at the farm, and plays Cupid between her and Pikey, an equally shy young thresher. His efforts to demonstrate the act of courtship to Pikey go awry when they are misconstrued by Pamela who sets her cap at Silas.
When Silas challenges the wirier Goffy Windsor to a five-mile race around the local countryside, Uncle George takes bets on the result and Silas is sure of victory. However, after suffering a series of ailments Silas realizes that he will have to cheat and, literally, take short cuts to win.
Uncle Silas has only one real rival likely to beat his roses in the forthcoming show - retired soldier Walter Hawthorn. Ned is fascinated by Walter's collection of military memorabilia; Silas is fascinated by 'Topsy' Turvey, the local district nurse. Will this diversion give Walter his break or is he falling prey to painful memories of the past?
Georgina and Abel have their first child, making Silas a proud grandfather. One of the guests at the christening is Georgina's friend Ellen, a professional cook, who knows the way to a man's heart and finds Silas as irresistible as most of the women he encounters.