On April 15, 2019, towards the end of the afternoon, an alarm goes off in Notre-Dame Cathedral in Paris. The premises are quickly evacuated and after a summary verification of the premises, everyone is brought back, believing the alarm to have been false. However, there is a fire, but it started in the frame of the building. As the blaze grows, it’s captured live by the capital's television channels. While the population watches in horror as this disaster that jeopardizes an irreplaceable world cultural heritage site, hundreds of firefighters try the impossible — to control the fire and save what can still be saved. The film partly uses studio reconstruction and also actual filming taken at the time if the fire.
Jean-Jacques Annaud, the director said “a truth often ignored by most people; they saw the fire from the outside, I am going to show them what happened inside, bring to life what was not seen and sometimes what was not known”.