Having vague flashbacks to some books I read in my youth.
One is where a group of youths are captured and placed in an environment of white staircases, they get food from dispensers according to some sort of pattern. The food is pellets I believe. I have a strong reccollection of there being a toilet in the center of a narrow beam between two sets of stairs.
The other is, I think, by the same author, and involves somone getting into the fourth dimension and being captured by the beings who live there. One of them is mean but its “partner” is kind I think. There was something about a lantern…
