The novel is set in the late 1920s. Walter Parrish, a fifteen-year-old schoolboy, is the only child of a conventional, conservative couple who are experiencing some marital problems. In consequence he is sent to stay with his Uncle Patrick and Aunt Leonie in rural Kent for the summer holidays. Walter’s relatives live in a cottage with an orchard attached, and the fruit that they grow provides them with a meagre income. Patrick was badly gassed in the First World War and is still a sickly individual when Walter arrives to stay with him, as Leonie explains:
“There are about eight things that he gets, singly or in combinations, all the time. The best thing to do is to reckon that he’s either fairly well, or rather ill, or very ill. The details are too complicated.”
As Patrick is confined to bed for lengthy stretches of each day, Walter spends much of his time in the company of his aunt. Leonie, aged twenty-six, is much younger than Patrick and, in Walter’s eyes, constitutes “a strikingly beautiful young woman”. Encouraged by Leonie’s tactility and open displays of affection towards him, the schoolboy swiftly falls hopelessly in love with her.
After a party held at the home of Colonel Masters, a neighbouring farmer, Walter ponders why Leonie seems to be so unpopular with the locals. She tells him that she is not in fact married to Patrick and that there is widespread disapproval of her in the district because the two of them are therefore deemed to be living in sin on what is officially church land. Walter is excited to realize that, as Leonie is not related to him after all, he is now free from any impediments that would have prevented him from making approaches towards her had she been married.
Masters is convinced that Leonie’s Alsatian Remus (“Remus isn’t a dog really. He’s a very intelligent person who just happens to look like a dog”) has been worrying his sheep, and tells Leonie that if he catches him amongst the flock then he will put a bullet in him. Leonie retorts in kind: “If you ever dared put a bullet in Remus, I’d put one in you”. The dog escapes from the cottage one night, returning just before dawn, exhausted and encrusted with dried blood. Walter and Leonie wash and scrub him so that he passes muster with an extremely suspicious Masters but when the dog elopes for a second time to run the sheep he is shot and killed by one of the farm workers.
Leonie now takes steps to implement her plan to exact deadly revenge on Masters, but Walter does not take her threat seriously, being far more interested in persuading the young woman to become engaged to him. She consents to his proposal if Walter, in return, will help her to kill the Colonel. He refuses and, to his satisfaction, persuades Leonie to abandon her murderous designs but not before he has unveiled a rudimentary plan (intended as a joke) that would allow Leonie to murder Masters and get away with the crime.
On the morning set for Walter’s return home, he discovers that Leonie has gone out armed with a gun and realizes that she was serious about killing Masters all along. Walter hurries off to the nearby copse that Leonie had selected for her assassination attempt, climbs a tall tree and is just in time to observe the woman point a gun at Masters as he takes an early-morning stroll through the woodland. The Colonel’s imposing physique, allied to the force of his personality, overwhelms Leonie: he disarms her, strips her to the waist and begins to make love to her in a rough but passionate fashion. Walter, all his dreams of marriage crushed underfoot, runs back to the farm, catches a bus to Canterbury railway station and sets off for his parents’ house in order to avoid seeing Leonie again.