Throughout Critical Mass, I kept thinking, What if? Not just the big What if? that arises in any novel concerning Holocaust survivors, but smaller What ifs? What if Martina Saginor had been born in a time and place where it was normal for a working-class woman to get an education? What if her mother had respected rather than scorned her intelligence? What if her daughter had known her?
Critical Mass opens with the first meeting between Martina Saginor and Sophie Herschel. Children in the same city but different spheres (Frau Saginor was the Herschel family seamstress), they became friends and after the Nazis invaded Austria, their daughters, Kitty Saginor and Lotty Herschel, grew up together as friends of last resort. Both escaped to London (along with Lotty's brother) on the Kindertransport and their families died in the Nazi death camps.
Lotty never liked Kitty, but decades later she still feels a duty to her childhood companion. When Kitty's drug-addicted daughter Judy Binder disappears, she asks VI Warshawski to find her. The search leads her to an abandoned rural drug house, but not to Judy, and VI returns to Chicago and meets with Kitty. Once there, VI discovers that Judy's son Martin (who inherited his great-grandmother's scientific genius and curiosity), has disappeared. As a favor to Lotty, VI begins another futile investigation, one that becomes critical when VI finds Kitty bleeding to death on the floor of Martin's bedroom. With her client dead, VI continues searching for Martin as a favor to Lotty and discovers a link between the drug house, Martina Saginor's forced labor in a Nazi camp, and the CEO of a corporation that feels like a combination of IBM, Microsoft and Facebook. Paretsky also weaves in flashbacks seen through Martina's eyes and a sort of closure for Lotty Herschel. Perhaps not quite as engrossing as Hardball, Critical Mass still ranks as one of Paretsky's best books. If you read it, don't skip the author's note - while the story is completely fictional, Martina Saginor was inspired by an actual scientist.