A "hugely entertaining" (Wall Street Journal) mystery starring "a Royal Tenenbaums-esque clan of geniuses" (Martha Stewart Living)--perfect for fans of Mr. Penumbra's 24-Hour Bookstore.

In this "riveting...brilliant" (Booklist) debut, Hazel Severy, the owner of a struggling Seattle bookstore, receives a letter from her adoptive grandfather--mathematician Isaac Severy--days after he dies in a suspected suicide. In his puzzling letter, Isaac alludes to a secretive organization that is after his final bombshell equation, and he charges Hazel with safely delivering it to a trusted colleague. But first, she must find where the equation is hidden.

While in Los Angeles for Isaac's funeral, Hazel realizes she's not the only one searching for his life's work, and that the equation's implications have potentially disastrous consequences for the extended Severy family, a group of dysfunctional geniuses unmoored by the sudden death of their patriarch.

As agents of an enigmatic company shadow Isaac's favorite son--a theoretical physicist--and a long-lost cousin mysteriously reappears in Los Angeles, the equation slips further from Hazel's grasp. She must unravel a series of confounding clues hidden inside one of her favorite novels, drawing her ever closer to his mathematical treasure. But when her efforts fall short, she is forced to enlist the help of those with questionable motives.

"A novel that is anything but clueless, filled with consideration and compassion" (The Washington Post), The Last Equation of Isaac Severy proves that, like Hazel, you don't have to love math to fall under the Severy spell.