Death by numbers

The subtitle of The Last Equation of Isaac Severy by Nova Jacobs is A Novel in Clues. How clever, maybe even a bit twee. Is Jacobs about to lead readers on a choose-your-own-adventure chase? In a way, yes.
This debut mystery is fun, but not necessarily light. In scene one, protagonist Hazel Severy, a 30-something failed bookseller, attends the funeral of her grandfather, the titular Isaac Severy, a mathematician of international repute. His death plunges his family and friends into deep mourning. Enter Philip Severy, Isaac’s son and near-professional equal. While Isaac dedicated his life to pure mathematics, Philip is a theoretical physicist obsessed with his place in the history of string theory. Enter also Hazel’s beloved brother Gregory, a member of the Los Angeles Police Department. Oh, and weird cousin Alex.
As Jacobs peels back the layers on the Severy clan, we discover that Philip is a professional prevaricator in his personal life, Gregory has some unresolved issues and Alex is as much of a liar as all the rest of them — and I have not even mentioned all of the rest of them.
When Hazel decides at the funeral to break the seal on a letter from her grandfather, she sets in motion one set of clues that will take her from a typeset puzzle to a mysterious pink hotel to — well, no spoilers. At the same time, the perspectives of Philip and Gregory show that there are darker layers in the family than Hazel knows. Philip is being pursued by the enigmatic P. Booth Lyons of an organisation called “Government-Scholar Relations” and Gregory is pursuing the greatest criminal he has ever known.
Isaac may have understood the dysfunction of his son and grandson, which is why he sends the confused and damaged, but also kind and honest, Hazel down a rabbit hole of his own making. If ever there were a book-length explanation of “a method to his madness”, this is it. Isaac plays a shell game with his beloved granddaughter that even involves a shell game (or at least, the explication of one).
If occasionally, going down the rabbit hole with Hazel seems digressive, that is all right. It staves off some heart-wrenchingly sad realities on the surface. Hazel and Alex get closer and closer to understanding Grandfather Isaac’s “last equation”, and it is a doozy — one that might explain Isaac’s death and many others as well. Jacobs has penned a novel that is anything but clueless, filled with consideration and compassion for the different levels of human damage and comprehension.