An unknown woman in a lovely cottage calling in her aged gardener, Alfred. She then squashes a wasp on a window pane.
Bobby Jones, ex-Navy lieutenant, is caddying for Dr Thomas, ex-corporal, on the clifftop golf course just outside the Welsh village off Marchmont. Bobby hears a scream, and the two rush to the cliff edge; they see a man at the bottom and Bobby scrambles down while Dr Thomas goes for help. The injured man opens his eyes and asks “Why didn’t they ask Evans?” then dies.
Bobby finds a picture of a beautiful young woman in the man’s pocket, along with a fountain pen and a key on a fish keyring. Another man appears on the cliff top and comes down to help, introducing himself as Roger Bassington-ffrench. He agrees to watch the body while Bobby rushes off to Evensong, where he’s playing the organ at his dad’s church. Lady Frances Derwent, a childhood friend of Bobby’s and daughter of local aristocrat Lord Marcham, is at the service.
Bobby’s dad has discovered Bobby is going into the car business with his friend Knocker. Their housekeeper Mrs Roberts serves them dinner. That night Bobby dreams about the woman in the photo coming to life.
Bobby and Dr Thomas are at the golf clubhouse when Lady Frances arrives for a game. The course is closed after the death. She and Bobby, who haven’t seen each other in years, reminisce on the cliffs. He tells her about the victim’s last words. She has seen in the paper that the body has been named: Alex Pritchard, identified by his sister Mrs Cayman. In the village, Knocker turns up to see Bobby.
The next day is the inquest. Bobby gives evidence, listing his many local odd jobs (he had previously run away to sea, presumably after his mother died). A forbidding man in a bowler hat arrives. Bobby doesn’t mention Pritchard’s last words to the inquest. Also called to give evidence is Amelia Cayman, an overdressed older woman. Bobby is surprised, as she doesn’t look like the woman in the photo he found, though Mrs Cayman claims it’s her. She tells the court Alex didn’t like to wear a knapsack, preferring to send parcels ahead to where he was staying.
Afterwards, the Caymans go to visit Bobby at the vicarage. He tells them Pritchard’s last words but they are flummoxed. They ask if Bobby knows any Evanses: “We’re in Wales,” replies Bobby.
Bobby is knocked off his bike when Lady Frances rides by. They discuss the inquest; Frankie has seen the woman’s photo and she says it does look like Mrs Cayman. They go for a ride and have an argument about snobbery, and Bobby’s upcoming job as a used car salesman. Frankie rides off in a haughty huff.
Bobby receives a letter from a Buenos Aires firm (though posted in Guildford) offering him a job with £1000 a year, and first class passage paid, starting in one week. He’d have to leave instantly, but Bobby is determined not to let Knocker down and decides against it.
The travelling carnival is in town and Bobby has a job working the waltzer for Mr Miller, the owner. Bowler Hat Man is standing near by with a red balloon. The local twins give Bobby a bottle of beer, a gift, they say, from Mr Miller. Frankie and her rich pals turn up. Bobby, after drinking from the bottle of beer, starts to stumble as the ride whizzes round. He collapses, his vision now spinning psychedelic colours.
Bobby wakes up in hospital with Dr Thomas and Frankie there. She is wearing his clothes; he had been sick on hers at the carnival. Bobby has consumed — and somehow survived — 30 grains of morphia, and they deduce it was probably put in his beer. Frankie says she’s going to look for Miller.
There is concern that Bobby meant to kill himself, though he denies this. Dr Thomas declares if he was going to kill himself he’d take a drug, not hang himself, because of the carpets and the cleaning up required. The doctor mentions John Savage, a millionaire who died by suicide thinking he had cancer, though an autopsy later revealed he didn’t. Dr Thomas also questions the job offer Bobby got: he’s made enquiries and the company doesn’t even exist: someone is trying to get Bobby out of the way. Dr Thomas leaves, unaware that Bowler Hat Man is sitting in the corridor with a bunch of flowers. Bobby picks up the local paper and, after reading an article which shocks him, leaves the hospital in his pyjamas. Bowler Hat Man has gone, leaving his flowers.
Frankie goes to see Mr Miller, who states he had nothing to do with Bobby’s poisoning. Bobby tracks the twins down in the village and questions them about the bottle of beer — they say they didn’t actually see Miller, as the man was masked.
Bobby runs out in front of Frankie’s car, and shows her the article in the local paper. It’s about the inquest and includes a photo of a young Mrs Cayman, allegedly found on Alex Pritchard’s body — but it isn’t the photo Bobby had found in Pritchard’s pocket. Bobby wonders to Frankie if the mysterious Bassington-ffrench swapped the photographs round when he’d been left alone with the body.
As Bassington-ffrench had claimed to be looking for a house to buy in the area, the two go to visit Frankie’s father, Lord Marcham, who knows everything about the area. Bassington-ffrench was also in the Navy; Bobby remembers the distinctive Navy salute he had given. Bobby calls Knocker to see if he, also an ex-Navy man, knows him.
In a tetchy chat with her mother, it transpires Frankie had been wearing one of her mum’s favourite dresses when Bobby was sick on her. Lady Marcham also points out to Frankie that the maid is the only person in a house who knows what’s going on. Outside, Frankie and Bobby discuss Pritchard’s last words and wonder who Evans is.
The privileged Frankie, with time on her hands, wants to sleuth and hypothesise their way to an answer. Bobby is less keen as he has committed to Knocker’s car sales venture. Bobby goes to the village and sees a crowd of people outside Dr Thomas’s home. The doctor has been found hanged in the hall in an apparent suicide.