The Department of Mysteries was the most secretive institution within the Ministry of Magic.
The wizards who worked there were known as "Unspeakables"—a title derived from the strict prohibitions they bore: they were forbidden to discuss their work with anyone or disclose any information concerning the department.
Precisely because their work was so completely confidential, outsiders were full of speculation about its inner workings, and rumors abounded.
There were even rumors that Cornelius Fudge used the Department of Mysteries to develop terrible poisons, secretly deploying them against his political rivals.
The Department of Mysteries lay on the Ministry of Magic's ninth underground level, accessible only by taking the lift.
Upon reaching the ninth level, one passed through the lift's grille and along a corridor to an utterly unremarkable, solid-black wooden door. Pushing it open led into a deep, circular room.
Everything there—the vaulted ceiling, the curved walls, the polished floor—was pure black, as though it had swallowed all light.
Cold blue flames flickered in the sconces on the walls, their faint light reflected in the mirror-bright black marble floor underfoot.
Twelve identical black doors stood within the circular room, without markings or handles, set at even intervals and fitted seamlessly into the pitch-black walls.
"Good afternoon, Crocker."
"Good afternoon." The man greeting Crocker was Dahl, an Unspeakable who worked in the Brain Room and specialized in studying the nature of thought.
Without breaking stride, Dahl headed straight toward one of the unmarked black doors.
"Things haven't been peaceful lately. Stay safe!" Dahl left that hurried warning before disappearing through the door.
Unconcerned, Crocker put away the Daily Prophet in his hands and muttered, "Broad daylight, with so many people in the Ministry... even if You-Know-Who had gone mad, he wouldn't choose a time like this..."
Crocker turned and stood before