In Paris, a young girl is found dead, wearing an evening dress. Commissioner Maigret investigates her murder and tries to uncover the truth behind her death.

I wake up gagged, hands and feet tied. I can see the clouds go by through the window. I'm in the back seat of a car. Who is this man driving? And where is he taking me?

One night, Zélie, a 7-year-old little girl, sees her young aunt Clara arriving at the family home. Clara is sad, does not leave the room and wears bandages on her wrists. Faced with the mystery of this closed door, Zélie understands that to bring her aunt out of her melancholy, she just needs to help her dissipate the clouds in her head...