The Wonder, review: Florence Pugh is rivetingly brilliant in this eerie period mystery

“We are nothing without stories,” an unseen woman (voiced by Niamh Algar) tells us in the opening scene of The Wonder, “so we invite you to believe in this one.” As director Sebastián Lelio makes immediately clear, the events we’re about to witness are a tissue of fiction.

This supremely eerie period mystery begins in a present-day film studio, with the camera roving over the plywood reverses of sets, looking for an entryway into the past. After a moment or two, it finds one: the interior of a small 19th-century ship, where Florence Pugh sits at a table, already in costume, poking at a bowl of stew and glancing pensively off to one side.

Of course, within seconds, you’ve bought into the fabrication: we actually are in a boat and this is actually Lib Wright, an English nurse sailing towards a highly unusual assignment in Ireland. But this strange opening gambit reminds you of the deal we make every time we set foot in the cinema: yes, we know the whole business is an elaborate game of make-believe. But isn’t life more beautiful – or maybe just more bearable – when we step into the lie and play along too?

The Wonder is about such acts, and pacts, of faith. One of them appears to be fixed in place in the remote village for which Lib is headed. She has been enlisted to keep watch over 11-year-old Anna O’Donnell (Kíla Lord Cassidy), who has reportedly gone without food for the past four months. The girl claims to be divinely nourished by “manna from heaven”, a claim endorsed by her flinty mother Rosaleen (Elaine Cassidy, who is Kíla’s own mother off-screen).

The level-leaded Lib is certain, however, that the miracle is a put-on, and becomes determined to uncover the truth. In this she has an ally: Tom Burke’s William Byrne, a sharp-witted, rakishly charming journalist from The Daily Telegraph – points for accuracy here – who has been sent by his editors in London to investigate.

Meanwhile, the village’s doctor (Toby Jones) and priest (Ciarán Hinds) treat Lib with barely disguised scepticism, even though she’s the sceptic and was summoned at their request. The murky prospect of ulterior motives begins to swirl, and Lib’s vigil becomes a furtive hunt for the story that this story – the one about the divinely favoured young innocent, suffering for the good of the world – was drafted to mask.

Adapted by Lelio, Alice Birch and Emma Donoghue, the Irish author of the abduction drama Room, from Donoghue's 2016 novel of the same name, The Wonder is another parable of confinement. Even the wide, heather-scuffed peatlands, stunningly shot by Ari Wegner, feel like they’re holding Pugh captive, while the interiors resemble Rembrandt canvases, with candles or shafts of sunlight brushing the gloom with silver and gold. Against all of these backdrops, Pugh is riveting: she makes you feel Lib’s mind pushing at the walls of this bizarre scenario, scratching for the chink in the fiction that will lead her to truth.

Cert 15, 103 min. On Netflix now