The Hugo's Brain is a French documentary-drama about autism. The documentary crosses authentic autistic stories with a fiction story about the life of an autistic (Hugo), from childhood to adulthood, portraying his difficulties and his handicap.

Julie Martial, impetuous and headstrong young editor, receives large red envelopes crimes committed just 24 hours later. Marc Simon, of the homicide squad, try to make the connection between the victims, who do not know and apparently have nothing in common. The case caused an outcry in the press, which refers to "the murderer with the ink stamp." Because the murderer signs his crimes with a number branded on the forehead of its victims. While Marc Simon and his men face this conundrum, Julia receives a letter of great concern: this time, the mass murderer describes his own death ...

A former history teacher-turned-municipal librarian tries to help local young people.