Mackay introduces us to April, 40 years on, making do for friendship with an irritating upstairs neighbour. She is a schoolteacher now, divorced and childless, clearing a space for herself in an overgrown London garden. Mackay, whose most passionate prose is reserved for nature, takes April back to Stonebridge, the village of her childhood, immersing us with relish in the small-time quiet of the country, "the hot still breath of cornfields and the took-took-took of hens." On the surface Stonebridge is a children's heaven, willow and alder, a water vole on a green island of crow's-foot in midstream, and the orchard of the title is "a dark-green and purple- blue paradise where bloomy plums dropped from the low trees into your hands." April and Ruby make a camp here in an abandoned railway carriage, adopting "the low hoot of the owl" as code. It is a private place to glory in their friendship and to stay safely out of reach of Ruby's bullying parents - that is, until Mr Greenidge appears.
In Mr Greenidge, Mackay has created a wonderfully sinister character. Jovial and modest, long-suffering and sly, with an invalid wife and a salami sausage of a dog called Liesel. On first meeting Mr Greenidge, April wonders if she's seen him before, and from that moment hardly a day passes that we don't come across him. He loiters with his dog in Lovers Lane, ambles past the school, and calls to April with the low hoot of the owl, so that she and Ruby are forced to switch to "the lone cry of the peewit" to outwit him. Mackay captures perfectly the passion and humour of their friendship, the shared books, treasures and jokes. But against this atmosphere of lightheartedness, of fairy-lights and teacakes, a small, sad drama is being played out.
April is invited to the Greenidges on Sundays to play with Liesel and cheer up the housebound Mrs G. "Bless me, I've gone and forgotten the sugar!" - and while April searches for it in the unfamiliar kitchen, Mr Greenidge comes up behind her and presses his body against hers, tickling her neck with his salt-and-pepper beard, "You won't tell will you?" And, of course, April is too polite to do so.
Mackay undercuts the warmth of April's family life with a real and creeping dread. Her parents, Betty and Percy, are cosy people with a period language of their own who fail to guess the cause of their daughter's distress.
For all the riotous descriptions of nature, the over-packed images too full of adjectives, this is a subtle book. Its themes are simply and beautifully constructed and the beguiling atmosphere of a Fifties childhood lingers on after the last page.
On April's return journey, in middle age, she passes the Greenidges' old house. "Sometimes, in memory, that pink quilted bed was as innocuous as a rose, and I think, what Mr Greenidge did wasn't really so bad." But with her next breath she remembers how he corroded her childhood with fear, anxiety and deceit, and we are reminded of the ability of children to push their suffering to one side.