The Monolith are quasi-religious cult that is hostile to all but their own, the Monolithians believe in the power of the Wish Granter, rumored to be an alien artifact hidden in the center of the Zone.

It is interesting to note that all Monolith stalkers are immune to the zombifying effects of Psi-Emitters, like the Brain Scorcher, and still retain their combat skills.

The Monolith members devote their lives to protecting the secret of the Great Crystal, ensuring that no one ever reaches the center of the Zone.