Twenty years ago, the poet, essayist and playwright Claudia Rankine, hailed for Citizen – an original, unnerving and unforgettable scrutiny of racism in the US and winner of the 2015 Forward prize – was involved in a more inward undertaking. She had been reading Virginia Woolf’s To the Lighthouse – and Woolf seems to have become for her, as happens to many readers, a muse of sorts. In the novel, there is a point at which Woolf’s Mrs Ramsay revels in a mind at liberty, “free for the strangest adventures” and observes: “When life sank down for a moment, the range of experience seemed limitless.” Rankine’s own project is about the imagined limits to that freedom. Her narrator is pregnant, uncertain whether to become a mother. Rankine was aware Woolf had decided against having children because of mental instability and her narrator wonders whether a mother and an artist can be expected to coexist. Plot is an arresting curiosity: an embattled, intense, extended prose poem, published in the UK for the first time.

Rankine, although a mother herself, was not pregnant when she wrote it. If there are autobiographical elements, they are stitched invisibly into narratives from elsewhere. It is a bracing, discomfiting and complicated read partly because it breaks a taboo. It is often oppressively assumed that women will necessarily rejoice at pregnancy but this work involves a complicated dredging of doubt, an examination of the visceral and cerebral burden of pregnancy, a deliberate losing of the “plot” (the word encompassing several meanings).

The work examines proximity and Rankine applies this to language itself. Her titles include Proximity of Inner to In Her – as if words were themselves were in danger of becoming codependent. Woolfian moments abound as Rankine homes in on the separate role of the artist (the influence of Lily Briscoe, Woolf’s artist in the novel, is never far away). Like much of her work, Plot is a painterly book and while words cannot be expected to behave like paint, there are bold, modernist attempts at verbal impasto here, as if pen and brush were a double act:

in the troubled gaze raining gutted streams a widening
self evolves having gulped until the brown of ground is
the blood of face.

The mother-to-be goes on to paint, more clearly, the river in which Woolf drowned:

She paints the River Ouse darker than its flow, its cloud-lined
exterior housing all that has rested in Woolf’s erased face.
She paints lightest the wind she breathes into. Beyond the self,
the land swells into an existence that is its own battle
Its largest stone – for her pocket – ensuring a river can slip
beyond her breath, out of her mouth.

Drowning gets cryptically caught up with pregnancy – a submerging of the self.

A second work fed this book: Ingmar Bergman’s 1973 television series Scenes from a Marriage, about a couple coming apart. Rankine has named her characters Liv and Erland, after the actors Liv Ullmann and Erland Josephson (Ullmann’s ability to embody pain unrivalled by any actor before or since) and “Ersatz” is the baby-to-be (his question-mark status confirmed by his name). In Interlude, Liv meets a woman for whom pregnancy is a reprieve, “a way to put the self she did not like behind her”. And by this point, the book is coming into its own as theatre as much – or more than – as art: the pregnant woman in the cafe is a dramatic presence in her cascading blue silk and her provocative sunglasses. And the question “Honey are you happy?” seems to hang in the air, easier to ask than to answer.

Or Passing the Time with Some Rhyme

Too much within – close the garage, reset
the alarm, let the eye in the world coo.
The River Ouse flows on no matter what
or who gets caught in its debris. She sits
in Le Café for once not distracted
by boo, its bark. She sits rudely sunglassed,
blue silk cascading off her tumultuous
tummy. Honey, are you happy? You there,
indiscriminate, in your loosened dress
skirting sidewalks. You there, flirting across
each shop window though a pastel broach moos
powdered jade, asking, Are you happily –
oh bovine, oh babe – are you happily
charmed? For this world, oh this whorl is a woo.

• Plot by Claudia Rankine is published by Penguin (£10.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply