the part where he goes to the Room of Sleep IS A GODDAMN NIGHTMARE
he starts in Ansem’s computer lab, which we also saw in the opening flashback of Dream Drop Distance
…puts in a CD, types the apprentices’ names as passwords, goes down to the Heartless factory floor—which is still pretty high up in the castle…
and he accesses another secret passageway and goes down.
Like, way down.
So far down you can only assume it’s the castle basement, or maybe even beneath the castle itself.
And what’s down there?
A whole hallway of prison cells with barred windows, chains, and passcodes needed to open them.
"The experiments caused the test subjects’ heart to collapse, including those of the most stalwart. How fragile our hearts are! My treatment produced no signs of recovery. I confined those who had completely lost their hearts beneath the castle."
THIS IS IT.
THESE ARE THE FUCKING CELLS THEY KEPT TEST SUBJECTS IN.
JESUS FUCKING CHRIST
ALSO NOTICE THE CHAINS ARE SHAPED LIKE AN X.