Cara Black’s riveting 18th installment in her New York Times bestselling Parisian detective series entangles private investigator Aimée Leduc in a dangerous web of international spycraft, post-colonial Franco-African politics, people’s resistance movements, and neighborhood secrets in Paris’s ancient and artisanal yet tech-centric 12th arrondissement.

Aimée Leduc is about to go onstage to give the keynote address at a tech conference that is sure to secure Leduc Detective some much-needed business contracts when she gets an emergency phone call from her infant daughter’s playgroup: Aimée’s own mother, who was supposed to pick Chloe up, never showed. Abandoning her hard-won speaking gig, Aimée rushes to get Chloe, annoyed that, yet again, her mother has let her down.

But as Aimée and Chloe are leaving the playground, Aimée witnesses the body of a homeless woman being wheeled away from the neighboring convent, where nuns run a soup kitchen. The last person anyone saw the dead woman talking to was Aimée’s mother — who has vanished. Trying to figure out what happened to Sydney Leduc, Aimee tracks down the dead woman’s possessions, which include a huge amount of cash. What did Sidney stumble into? Is she in trouble?