Frances Hardinge’s last novel, The Lie Tree, won the overall Costa book award in 2015; the only other children’s book to have done so is Philip Pullman’s The Amber Spyglass, in 2001. Hardinge is at the forefront of children’s fiction, with a rich, unusual taste for language, an eye for the striking and apt image and stories that reveal a staunch defence of the weak and the oppressed. What is more, she combines a subtle, intellectual approach with plots that swoop and soar.

Her darkly splendid new book is a worthy follow-up to The Lie Tree, set just before the start of the English civil war. Hardinge has always been interested in splits and doubles; in how a character, apparently good, can be only a sliver away from being bad; in how perceptions and opinions shift according to perspective and situation. Her heroine in Cuckoo Song was a fairy changeling, unaware that she had been created and placed into the family that she thought hers; Faith in The Lie Tree must fight against the strictures placed on women in the 19th century, while unpicking a web of falsehoods around her scientist father.

Makepeace, the protagonist of this new book, also faces a mystery around her birth, and is surrounded by a similar web of lies. All these girls are born into power structures that appear to constrict; all learn that things can be made more malleable.

The central themes of A Skinful of Shadows are inheritance and power, and how these link to governance both literal and psychological. An aristocratic family, the Fellmottes, possess an unusual ability. They can catch ghosts and absorb them into their own minds. Makepeace, being a bastard daughter, is tracked down by the family, who wish to protect their property and bloodline at all costs. And yet, as Makepeace discovers, her mother fled from them, and, as her last wish, begs her to flee too.

Hardinge is adept and vivid in creating a sense of terrifying, apparently permanent grandeur: the Fellmotte house, Grizehayes, is ancient, implacable and vast; Lady April, one of the family, treads over the outstretched palms of an underling rather than get her dress wet. It is not hard to see a critique of aristocracy: should some families, here quite literally in thrall to their ancestors through their ghosts, be any more suited to power than others? The damage done as a result is incalculable.

Hardinge gives the opposing Puritans a similar kind of treatment, with their inconsistencies and excesses laid bare, and it is to her great credit that she delineates the attractions and horrors of both sides, symbolised in the characters of James, a bastard tempted by nobility, and Symond, the noble heir who seems to shift allegiance. Makepeace, travelling from one camp to the other, reads news sheets of the same battles from both sides, each proclaiming loudly that they, and only they, are right. The problem of echo chambers and fake news is an old one. The most appealing characters here are the in-between ones: the spies, roustabouts and uncoverers of nuggets of information, those who risk their lives not in the service of ideology, but in the service of life itself.

Thanks to large amounts of gold, the Fellmotte family have managed to persuade Charles I not to expose their supernatural dealings. Makepeace must navigate these tricky territories, while staying true to her brother James and managing the increasing number of ghosts that pop into her head (including a wonderfully sniffy doctor, a reformed Puritan and another, more mysterious being). What gives the book its strength is the essential fairytale backbone of a girl going out into the world to achieve, and to reach a higher level of existence.

Perhaps in response to the Puritan elements in the story, Hardinge’s language in this novel is less elaborate than it has been, resulting in a cleaner, sharper diction. There are many wonderful moments that have the unmistakable Hardinge tang. Makepeace accidentally absorbs the ghost of a bear, symbolising both the uncontrollable id that she must subdue and the violence threatening to tear apart the country in “surprising zigzags”. She develops a deep rapport with her beastly fellow traveller, but often it’s “like reasoning with a thundercloud”.

The pull of the story is towards subversion, and Makepeace ends by reappropriating her inherited gifts, and using them not to provide a vessel for antiquated mores, but to succour the weak and the dispossessed. This is a wonderful, resonant narrative whose subtlety and insight will challenge, entertain and enchant.

Philip Womack’s latest book is The Double Axe (Alma).

• A Skinful of Shadows is published by Macmillan. To order a copy for £11.04 (RRP £12.99) go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99.