The "Solarium" was not a place of relaxation. In the show’s lore, it was a top-secret government installation located beneath the ruins of a 14th-century castle in South Bohemia. Episode 13—the final, never-officially-aired installment—supposedly documented a catastrophic failure of the facility’s radiation shields during a "chromotherapy session," resulting in the slow, grotesque mutation of the inhabitants.

The next time you have a sleepless night, type into a search bar. Read the forums. Watch the fan edits. Listen to the 47-second audio clip. Just don't do it alone. And if you start to feel warm—if your screen seems to glow a little too brightly—close the laptop.

three former employees of the Jáchymov sanatorium (which is a real location, now a museum) have anonymously stated that Basement Level 3 is "permanently sealed with concrete" and that "guides do not take visitors there after 1:00 PM."

A solarium is designed for healing: light therapy, vitamin D, warmth. In the show’s fictional universe, the Czech government weaponized this. They built —a "quantum solarium" that used concentrated radiation to "erase undesirable memories" from dissidents.