Watch FilmoFlix. In 1812, Napoleon I set off for the Russian Campaign and planned to spend a night in Châlons-sur-Marne. However, as the police were aware of a planned assassination attempt, the place of accommodation was changed at the last minute, and the house of Doctor Mathieu was requisitioned. But Doctor Mathieu was an opponent of the Emperor who had allied himself with the instigators of the attack. They decided to plant their bomb in the doctor's home, leaving his family in danger.