The Ashby family consists of Miss Beatrice Ashby ("Aunt Bee"), a50-ish spinster, and the four children of her late brother Bill: Simon, 20; Eleanor, 18–19; and twins Jane and Ruth, 9. Bill and his wife Nora died in an airplane crash eight years before. Since then, the Ashbys, like many old families, have been short of money. Bee has kept the estate going by turning the family stable into a profitable business. The Ashbys breed and sell horses, train horses, andgive riding lessons. All of them except Ruth ride frequently and work with the horses. The young Ashbys ride in equestrian competitions and win prizes. There is also great-uncle Charles Ashby in the Far East. Charles is coming home for Simon's 21st birthday, which is in a few weeks, though he will be a month or so late.
When Simon turns twenty-one, things will change: he comes into a large trustfund left by his mother. He is also the heir to Latchetts. Simon had a twin brother, Patrick, who was 15 minutes older. But soon after Bill and Nora died, Patrick disappeared, leaving what was taken as a suicide note.
The title character, Brat Farrar, is a young man recently returned to England from America. He was a foundling. At the age of 13, the orphanage placed him in an office job, but he ranaway instead. He ended up in the western U.S., where he worked at ranches and stables for several years, and became an expert horseman.
On a street in London, a complete stranger greets Brat as "Simon". He is Alec Loding, a second-rate actor. Alec's real name is Ledingham, and the Ledingham estate (now sold off for debts) was also in Clare. He knows the Ashby family intimately, and even afterBrat identifies himself, Alec is certain that Brat is an Ashby. The family resemblance is that strong — including the love of horses.
This gives Alec an idea: Brat should impersonate the missing twin, Patrick, and as the elder brother, claim the trust and the estate. Alec remembers a great deal about the Ashbys, Latchetts, and the village, and this, combined with his photographs and othermemorabilia will allow him to coach Brat on all the background details, and in return Brat will give him a share of the money. Barring a misstep on Brat's part, there is little to distinguish between himself and Patrick: neither has distinguishing scars or birthmark and the Ashbys' dentist and all his records were destroyed by a German bomb. Conveniently, Brat left the orphanage at nearly the same timethat Patrick vanished. Brat is reluctant – but tempted, especially by Alec's insistence that he must be an Ashby, which makes him want to find out about his possible family. He agrees.
After two weeks of tutoring, "Patrick" appears at the London office of Mr. Sandal, the Ashby family solicitor. Sandal is astonished, but convinced. "Patrick" says he adopted the name "Brat Farrar" after running away,and gives his own story as the account of "Patrick"'s missing years. Mr. Sandal informs Bee, who meets "Patrick" and is also convinced. Over the next two weeks, Sandal verifies "Patrick"'s story.
"Patrick" now comes to Latchetts. Ruth and Eleanor accept him, though Jane is hostile at first. Simon professes to accept him, and shows no apparent resentment at being displaced as heir. But Brat cantell that Simon is not deceived. Brat wonders why Simon seems to be certain that "Patrick" is a fake, and why he keeps silent.
"Patrick" settles in at Latchetts, and is accepted by all of the neighbors; he makes a few errors, but these are easily explained by seven years of absence. He has a home and family for the first time in his life. He becomes particularly fond of Bee, and feels guilty...