Good as it is, I worry a little about this month’s graphic novel. Will readers stick with it long enough to reach the twist that makes the effort of reading its first half worthwhile? I can’t be sure that everyone will – and yet, I must not spoil this twist, even in the cause of encouragement. All I can tell you is that this is a book that requires investment; that eventually something unexpected happens, a left turn that takes the story slyly in the direction of science fiction and in doing so tips the whole thing clean upside-down. Thereafter, the reader must carefully reassess everything they thought and felt about all that preceded it and only then will they understand just what a clever and uncompromising comic Paul B Rainey has created.

But what does the reader feel initially? For a long time, Why Don’t You Love Me? appears to be an unrelentingly grim account of the lives of a couple, Claire and Mark, whose relationship is in deep trouble. While Claire is depressed, drinks too much and spends her days in bed, Mark is in a state of permanent anxiety from the moment he wakes up on the couch downstairs. Newly returned to his job as a web manager following a period of sick leave (also for depression), he has no idea how anything in the office works. The pair have two children, Charley and Sally, but they’re neglectful parents. The TV and the Xbox are their babysitters of choice; sometimes, they struggle even to remember the kids’ names. Rainey uses an old-fashioned strip format, in black and white, as if his story had appeared first in a daily newspaper, the words “Why Don’t You Love Me?” appearing at the top of every one – and after a while, it’s a question the reader hardly struggles to answer. Whatever problems they might have, Claire and Mark are pretty horrible. What a pair of nihilists.

But are they really? Is it possible they’re simply trapped in a realm they cannot control? Paul B Rainey won the Observer’s graphic short story prize in 2020 and it’s great to see him between hard covers now. I love the way he draws people: Mark without eyes behind his glasses, Claire’s face completely featureless when the black dog is doing its worst. Their world never extends much beyond the sofa and the TV – the furthest they ever go is the pub – but Rainey imbues it with a claustrophobia so intense, it’s almost a character in itself.

It’s true that the book’s twist, already praised by Neil Gaiman, is powerfully redemptive, but even without it, he has plenty to say about modern life; how lonely it can be and how savage. His comic reminds me slightly of Black Hole, Charles Burns’s classic, highly metaphorical graphic novel of adolescent angst. Like that book, it is full of ordinary, everyday fear. There is a sense throughout of paths not taken and lives not lived. In the end – again, I don’t want to give things away – its message has to do with time and how it’s always running out: for us and for the planet. I can’t honestly say that reading Why Don’t You Love Me? is an uplifting experience, but it does have a strange urgency that is all its own.

• Why Don’t You Love Me? by Paul B Rainey is published by Drawn & Quarterly (£18.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply