When Parisian private investigator Aim e Leduc picks up the phone one hot July afternoon, the call turns her life upside-down. The voice on the other end, with its heavy German accent, belongs to a woman named Jutta Hald. Jutta claims to have shared a jail cell with Aim e's long-lost mother, a suspected terrorist on Interpol's most wanted list. If Aim e wants to learn the truth about her mother, she is to meet Jutta at a rendezvous point in an ancient tower in the Sentier. But when Aim e arrives, Jutta is dead, shot in the head at close range.

Aim e realizes she has stumbled into something bigger than Jutta let on, and that her own life is in danger. She has a lot of unsolved mysteries in front of her: Jutta Hald's murder, resurfaced materials from Sydney Leduc's terrorist activities in the 1970s, police suppression of important information. The question is, can Aim e put the pieces together before someone else ends up dead?