There’s a game you can play when reading book reviews, guessing what the critic really means. ‘Disturbing’ means ‘worried for the author’s mental health’. ‘Luminous’ means the reviewer has run out of synonyms for ‘good’. ‘Glorious’ means ‘fun’, but fun in a tasteful and unchallenging way. Aside from being clichés, these phrases function as a literary code; they usher books to their target readers, a siren audible only to those conditioned to hear it.