An essential reference in Heretics of Dune is an understanding of who Leto II is and the concept of the Golden Path. Leto is the son of the Fremen Chani Kynes and Paul Atreides, the hero who rises and falls in the first three novels. Like his father, Leto possesses extraordinary skills of prescience and ancestral memories. However, Leto does what his father couldn’t do: set in motion the Golden Path he sees in his visions. The Golden Path is a millennia-long course of genetic breeding and social conditioning to create a resilient humanity that can survive the battle at the end of the universe. Heretics of Dune, which takes place 1,500 years after Leto’s death, is the first inkling into whether the Golden Path worked. 

The Golden Path required two necessary outcomes that Heretics of Dune frequently references: the Siona gene and the Scattering. To fight human extinction, Leto devised a breeding program to produce a gene that would prevent predatory prescient forces from detecting humans. Siona Atreides is the first person to have this trait, and by Heretics of Dune, many people carry the Siona gene. The Scattering is the necessary exodus after Leto’s death to spread humans across the universe, making them difficult to find and allowing the Siona gene to reach diverse populations.