Esther is an illiterate seamstress in New York in 1905, stitching lingerie for society dames and prostitutes. She's 35, a melancholic virgin, and she starts a correspondence - helped by her landlady - with a labourer she doesn't know who's working on the Panama Canal.
It sounds unpromising, but American dramatist Lynn Nottage's ten year-old play, soaked in ragtime, blues and sad dreams, co-produced by the Park and the Theatre Royal Bath, and directed by Laurence Boswell, grips like a vice in the skilfully schematic unravelling of Esther's emotional crisis.
Above all, it's beautifully acted by the cast of six led by Tanya Moodie - so outstanding last year in Fences opposite Lenny Henry - as Esther, a plain and deserving woman who feels that life is passing her by, despite the support of the landlady (vividly done by Dawn Hope). She lives for the letters from George (Chu Omambala); before they even meet, she agrees to marry him.
In one extraordinary telescoped scene in the second act, that marriage is laid bare between the honeymoon bedroom, where Esther and George trade family histories for the first time, and at the kitchen table the next morning.
"An acrid smell of disenchantment hangs over the proceedings"
And the texture of Esther's life, which began picking berries in North Carolina, is defined in scenes with a dipsomaniac and lonely society dame, Mrs Van Buren (Sara Topham), who receives Esther in basque and white stockings in her boudoir; and with piano-playing Mayme (Rochelle Neil), a neighbour in the rooming house with a string of gentlemen callers.
In a play that is like an artfully animated photograph album, designer Mark Bailey provides a split-level arrangement of scenic panels that open to show Mayme's piano room, the clanging workface in Panama, Mrs Van Buren's "lifestyle" in a gilded mirror and chandelier, and the drapery store where Esther strikes up a touching friendship Mr Marks (Ilan Goodman).
A jacket of Japanese silk becomes a talismanic item in the story, which also deals in a frank discussion of sexual overtures and the vanity of human wishes when it comes to presenting yourself as an object of desire to others.
An acrid smell of disenchantment hangs over the proceedings, not least when Mrs Van Buren, increasingly dependent on the brandy bottle and Esther's visits, bemoans yet another visit from the in-laws - "the frog and the wart."
There's a whiff of a sexual politics agenda, too, but that is soon dispelled by the detail and accuracy of Nottage's writing - plays of hers already welcomed here include Fabulation at the Tricycle and Ruined at the Almeida - and the poise, power and serenity of Tanya Moodie's performance.