The Theory of (Not Quite) Everything is the first novel by South African-born British author, Kara Gnodde. For thirteen years now, ever since their parents’ tragic deaths, Mimi Brotherton has looked after her older brother, Art in their family home at 19 Muriel Grove. Professor Arthur Brotherton is a talented mathematician and “the deal of her life has always been: she is ordinary so that Art could be special.”

Early on, Mimi realised that “She’d have to stay home, reduced back to a data point in the great grand story of her genius brother and his all-important maths.” But now she’s finally decided to give up the museum job she hates, team up with her best friend Rey as a Foley artist, and look for romance. She goes for online dating, and gets Art to check out the sites to find the one with the best algorithm.

Art applies maths to the problem and (of course) has a theory for finding the right partner for his sister: having estimated how long she is prepared to search for the ideal partner, he informs her that “after thirty-seven percent, you settle on the very next man who is better than the ones who have gone before. That is the moment you can stop wondering if there is someone better out there. In all likelihood, there is not.”

But then Mimi meets Frank Taylor at a Mathematics Awards night. Frank is a mathematician too, so why isn’t Art pleased? Frank makes her feel truly loved; could Art be worried only about his own welfare? If Mimi leaves with Frank, he’ll have to fend for himself, and that would be a major distraction from his important work.

Art’s main research is on p versus Np, but he’s (perhaps excessively) paranoid that someone, the wrong someone, is stealing his work and will get there before him. It’s not the prize money he cares about; it’s the potential damage the wrong person might wreak with such powerful knowledge. And his suspicions have ramped up since Frank has appeared on the scene. Has Frank been entirely honest with Mimi?

After a nasty spat between the siblings that involves a pepper grinder and a broken wrist, Mimi goes away to break the tension. It’s during Mimi’s short absence that Art is hit by Frank’s car and ends up in an induced coma, with a severe brain injury. Frank swears it was an accident. Can Mimi believe him? Will she lose her brother? And if he survives, will Art lose his maths?

Gnodde’s story is original, her quirky characters easily endear themselves to the reader, and there are a few red herrings and distractions to build the intrigue and keep the pages turning. It is tightly plotted ensuring that even the most astute reader is unlikely to figure out all the angles.

Gnodde’s story touches on grief and guilt, on feeling abandoned, loneliness and loyalty, and, of course, love. Gnodde has a marvellous turn of phrase: “She even made them up in her head when Art wasn’t around, his opinions serving as guardrails to her bouncing thoughts.” This debut novel is funny and moving, and Gnodde’s next work will be eagerly anticipated
This unbiased review is from an uncorrected proof copy provided by NetGalley and Pan Macmillan.