In the "Prelude to Dune" series, it is revealed that Jessica's mother is in fact Mohiam; according to the authors, this fact was pulled directly from Frank Herbert's working notes for the original "Dune" series. In the storyline, Mohiam blackmails the homosexual Baron Harkonnen into a sexual encounter; when the first daughter she conceives proves genetically undesirable, she is forced to return. At this point the Baron drugs and viciously rapes Mohiam, and in retribution she secretly infects him with the disease that will later leave him horribly obese. The daughter born of this second union is Jessica.