This gripping tale of power, cruelty and all the consequences – the title’s reference to Joseph Conrad’s novel hints at the themes – was first published in 1973, and it seems extraordinary that it has been largely forgotten until now. In a new edition, with a foreword by Ottessa Moshfegh, the novel describes, to begin with, the upper-class English childhood of Giles Trenchard, referred to in fairytale cadences as “the Prince” – his mother and father are “the Queen” and “the King”.

It’s not very long before we see behind the cheerful confidence of the narrative voice, which treats the good side of Giles’s upbringing (he is “fed… with kisses and licks of sugar”) like the bad: “On his narrow shoulders and tight little bottom there are pale marks of old bruises.” Life around him is baroque, with his grandfather’s sexual activities a particular jaw-dropper.

Inevitably, Giles – who is “not satisfactory” to his father, and “a miserable worm” – is sent to boarding school, where he adopts a protective mask, enduring and clinging on through beatings and humiliation. “Ledge after ledge, summit after summit stretch upwards. There is no end.” Peppered through the story of his life are little interruptions – “Ladies and gentleman of the jury, you see before you a privileged young man” – that suggest we’re heading for a revelation.

War follows – a natural step for a young man who has always lived in a state of war – and then peace, which is worse. The style becomes angrier and more complex. “It’s so small, England. It’s so fucking small,” Giles reflects. The explosion that eventually follows is not entirely surprising, but it is satisfying and apt.

This novel – full of horrors but energetic, funny and tense as a spring – is one of four written in the 1970s by Brooke, who lives in London and has published no fiction since. Fathers feature prominently in her books, rarely positively. Lord Jim at Home, inspired by a real story but full of the kind of truth only fiction can deliver, plants its devilish brilliance deep in the reader and won’t let go.

• Lord Jim at Home by Dinah Brooke is published by Daunt Books (£9.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply