A doctor gets obsessed with the case of a dead woman after learning that the woman had died shortly after having rung her door for help.
The efficient Dr. Jenny Davin works hard and has been chosen to replace Dr. Habran, who has just retired, at the Kennedy Hospital. One night, someone rings the bell of her office after-hours and Dr. Davin asks her trainee Julien to not open the door since it does not seem to be an emergency. The next morning, Police Inspectors Ben Mahmoud and Bercaro require her surveillance tape since a teenager was found dead on the other side of the road and they are investigating what happened. Jenny feels guilty for not opening the door and becomes obsessed about finding the teenager's identity. Her investigation soon begins to affect her relationships with patients.