Solly Bertone, whose real name is Solange Berton, is ending her 32-year career as a senior flight attendant on Hexagone Air flights. After five years of enduring domestic flights with the low-cost subsidiary, she is hoping for one last prestigious trip. But during her final briefing at Roissy, she discovers that she has been assigned to a flight to Bergerac, a destination that infuriates her.

Several notables from the Chamonix region are found murdered in their homes. To move forward with investigation, police captain Thomas Delhaye decides to release Juliette Hémon from prison, imprisoned for a strangely similar case.