Written by Marceau, Gianguido Spinelli, and Jacques Deschamps, the film is about a police inspector, struggling with depression following his wife's death, who investigates a suspicious missing person's case at the request of a mysterious woman.

Filmed on location in Normandy, France, Trivial is the second feature-length motion picture directed by actress Sophie Marceau.

After six months in a mental hospital following a suicide attempt, the disheveled and lonely Le Havre police lieutenant is still haunted by visions of his wife.

After a quick search, he finds the room which is decorated with old framed photographs, portraits, and mementos of Bérangère's deceased first wife—a film actress who looks like the mysterious woman he met in his car.

Old newspaper clippings reveal that the actress, Victoria Benutti (Sophie Marceau), died in a car accident in 1970, exactly 36 years ago to the day of Bérangère's disappearance.

While investigating the crime scene at the foot of the cliffs, Renard spots the mysterious woman watching from a distance, and chases after her following her Volvo.

Renard drives to the cemetery where Victoria (and his wife) are buried and finds the mysterious woman's Volvo with a DVD inside labeled "Lucie 1982".

Looking for Lucie's address, Renard steals the hospital computer containing patient records and goes out searching for her, with his partner Pierre in hot pursuit.

After Pierre bails him out of jail, Renard goes back to the morgue convinced that the body belongs to some tramp, not Bérangère whom he now knows has been molesting Lucie and controlling her for years.