The Ukrainian melodramatic series "The Formula of Happiness" tells the story of Denis Demidov, a successful manager who accidentally hit a fisherman in a state of drunkenness. The protagonist decides not to tell anyone about the incident, but a few days later he dies under mysterious circumstances. His widow, Inna, is determined to find out the cause of her husband's death at any cost. After some time, she becomes the main suspect in his murder.