In a fumigation centre in Havana, Mayelín has the ungrateful task of fining citizens who infringe sanitary regulations. Apart from fighting dengue and disciplining her workers, she is, herself, under pressure from one of her supervisors. Mayelín must learn to find her place within a stressful and sometimes aggressive work environment.

The life and work of Cayita Araújo, teacher of revolutionaries, who has devoted her intelligence and courage to the struggle for the cause of the Cuban people.