Agents Of Dreamland by Caitlín R. Kiernan

A hard‑boiled government operative is pulled into a secret investigation of a desert cult whose ritual practices and cryptic transmissions point to an ancient, otherworldly intelligence; chasing fragments of evidence through bureaucratic denial and escalating nightmares, the investigator and a small circle of allies must unravel the cult’s occult network before a reality‑shaking event can be completed, confronting cosmic horror, personal loss, and the fragile boundaries between waking life and dream.

Purchase from Bookshop.org