Last Equation of Isaac Severy

Days after the mathematician Isaac Severy dies in an apparent suicide, his adopted granddaughter Hazel gets a letter from him in the mail. Hazel runs a struggling bookstore in Seattle. Isaac writes that a secretive organization wants his final equation, and he asks her to deliver it safely to a colleague he trusts. First she has to work out where he hid it.

Hazel travels to Los Angeles for the funeral and soon sees that other people are hunting for the same work. The equation could do serious harm to the extended Severy family, a group of brilliant, difficult relatives thrown off balance by the loss of their patriarch. Agents from an unnamed company follow Isaac's favorite son, a theoretical physicist, and a long-lost cousin turns up in the city without explanation.

Isaac left a trail of baffling clues inside one of Hazel's favorite novels, and each one moves her nearer to the equation. Still, it keeps slipping away from her. When her own efforts fall short, she has to ask for help from people whose motives she has reason to doubt.

This is a literary mystery that blends a family saga with a treasure hunt through a book. The tone is bookish and puzzle-driven, with a threat that builds as Hazel's circle of allies shrinks.