Under the Unmoving Sun is a one-shot adventure for the game Fire Burns Low. Player characters become strangers in a strange land when they are abducted from their homes and wake in the dark. What follows is a mystery that unfolds as they explore their new home. Before long, it becomes clear that nothing here is what it seems. Discover the nature of this place, and the puppet masters behind the scenes who keep you trapped there. This one-shot adventure was designed for the game Fire Burns Low but includes an adaptation for Dungeons & Dragons 5e with stat blocks for NPCs and monsters. It plays over 3-4 sessions. The file includes an appendix of monsters adapted for D&D 5e, a map, a brief, and a quick reference.