Creation Lake by Rachel Kushner

Sadie Smith – a 34-year-old American undercover agent of ruthless tactics and bold opinions – is sent by her mysterious but powerful employers to a remote corner of France. Her mission: to infiltrate a commune of radical activists influenced by the beliefs of an enigmatic elder, Bruno Lacombe. But just as she is certain she’s the seductress and puppet master of those she surveils, Sadie becomes caught in the crossfire between the past and the future…