Title: Civil War #0 (2016)
Writer: Brian Michael Bendis
Artist: Olivier Coipel
Colorist: Justin Ponsor
What are the Terrigen Mists?
The Terrigen Mist is a natural mutagen, arising as a vapor from the Terrigen Crystals, which are able to alter Inhuman biology. The Mists were discovered by the Inhuman geneticist Randac approximately 25,000 years ago. He immersed himself in the Mists and gained mental powers comparable to the Eternals. Sometimes the mutated subjects gain superhuman abilities; Medusa, Black Bolt, and Kamala Khan are three examples of this.
However, in the past, uncontrolled exposure to the Mists (due in part to Randac wishing for all the Inhumans to undergo Terrigen treatment or Terrigenesis) mutated the majority of the Inhuman population into hideously deformed monsters. After centuries of eugenics and birth control, the Inhumans managed to mitigate the genetic damage and cultivated a more responsible use of the Terrigen Mists. The practice they developed was to let only genetically perfect specimens undergo the random mutations provoked by the Mists.
Their theory was that genetic screening could avoid the risk of hideous and animal mutations in an individual. However, there are examples throughout the Inhumans’ canon where an exposed Inhuman became a devolved, sometimes mindless, evolutionarily inferior throw-back. The term Alpha Primitives was coined for these unfortunate outcasts of Inhuman society, who would for centuries become the breeding stock of a slave race. Resentment at this caste system sometimes bubbles up, and the Alpha Primitives have tried to overthrow their rulers in multiple storylines, often as a result of manipulation by a third party.