The opening pages of Edward St Aubyn’s new novel – his eleventh – may surprise readers familiar only with his highly successful Patrick Melrose series. That five-novel saga depicted the author’s well-born, horrifically damaged alter ego, and was written in a clipped and clinical style, a very mildly modernised version of Evelyn Waugh’s or Anthony Powell’s icy observational mode. Parallel Lines kicks off with what sounds more like Beat poetry. ‘Cows needed three or four stomachs to rip apart the tough fabric of the universe,’ reflects Sebastian, gazing out of the window at bucolic surroundings. ‘To break down the cellulites,’ he muses, ‘or cellophane, or cell mates, there was a word for it, the cell phones that bound everything together.’

Sebastian, a schizophrenic, is in the suicide observation room of a psychiatric hospital. He has been referred here by his psychoanalyst, Dr Martin Carr, who generally savours the time he spends with his ‘most traumatised patient’. He’s captivated by the lyricism of Sebastian’s free associations, which are tinged with the occasional metaphysical insight. Also, it feels rewarding to work with someone who actually deserves help, rather than indulging the ‘opulent … self-regard’ of some of the clients he receives at his home practice in Belsize Park. But Sebastian also presents Martin with an unusual professional problem. Martin’s daughter Olivia is Sebastian’s twin sister, though she doesn’t know it yet.

The siblings were separated shortly after birth and packaged off towards markedly different futures. Olivia, a former Oxford research scientist specialising in epigenetics, is now a radio producer. She has an infant son, Noah, with Francis, an ecologist who runs an NGO in Ecuador monitoring the destructive effects of heavy industry. Her latest project is Apocalypse, a series about ‘the six most likely causes of the next … great extinction’. Talk at the dinner table tends to revolve around the Anthropocene and how it probably won’t end well for the species that created it.

Parallel Lines is a continuation of the story introduced in St Aubyn’s last novel, Double Blind (2021). Like his earlier non-Melrose novels On the Edge (1998), a satire about New Age spirituality, and A Clue to the Exit (2000), a being-and-nothingness-saturated work of metafiction, and to some degree his satire of the Booker Prize, Lost for Words (2014), it belongs to a genre that British readers have long been considered averse to: the novel of ideas. Reviews of Double Blind seemed to confirm that such a bias exists, with critics complaining that the scientific and philosophical interludes got in the way of a tightly ordered plot and rounded characters. 

It’s notable that St Aubyn’s publisher has refrained from presenting Parallel Lines as a sequel, and the novel stands ably by itself, requiring no prior acquaintance with the characters or themes. Although Martin guessed Sebastian’s true identity in Double Blind, it is only here that St Aubyn draws out the dramatic potential of the situation: the analyst vacillates about telling all, and the separated twins inch closer to discovering the truth themselves. It’s a less taxing read than its predecessor, in which characters conducted what the author called ‘internal debates’ on topics such as the origins of consciousness and the limitations of the physicalist orthodoxies of modern science. This isn’t to say that the novel shies away from weightier concerns. There’s a repeat appearance from an entrepreneur named Hunter Sterling, who has sold his company Happy Helmets, a start-up in the ‘trans-cranial stimulation game’, and spends his time trading wisecracks with his ultra-high-net-worth friends about the latest breakthroughs in neuroscience and quantum mechanics.

St Aubyn is too old-fashioned a writer, though, to linger in abstraction. Sebastian’s tribulations provide the element of human interest that, according to many of the reviewers, was undersupplied last time around. When the anti-psychotics are working properly, he’s uncommonly good-natured, helping the more privileged but jaded people around him to appreciate small, everyday pleasures (‘You say incredible things, Seb, you should be on TV,’ the hospital’s art therapist tells him). And the novel is rooted in an essentially humorous English tradition. As in many of St Aubyn’s previous books, the action builds up to a climactic party scene. The occasion is the opening of an exhibition of the installations of an acclaimed artist, James Turrell, whose work blends, in Francis’s admiring words, ‘psychology, and physics and meditative practices, and astronomy, and aviation’. Characters who weren’t supposed to bump into each other do; Martin’s professional ethical dilemma is resolved, but not in a way he would have liked. It isn’t hard to imagine the whole thing on stage, albeit back when Noël Coward still ruled the West End.

Society comedy, with the odd blast of farce, may not be the ideal vehicle for the exploration of ‘ideas that def[y] common sense’ (the words come from one sceptical character, eavesdropping on a high-flown chat). A more formally ambitious approach might have allowed the cerebral talking points to be treated with greater expansiveness. Parallel Lines is entertaining, tidily put together and, when St Aubyn subdues his fondness for rambling metaphors, sparklingly well written. Yet, for all the deep research on which the novel clearly rests, the final effect is slight.