My pulp paperback edition states that it was originally published 1971 in Cracow, Poland. The node on Stanislaw Lem says otherwise. My version's cover is a drawing of dozens of squares systematically arranged and elevated against a red/orange gradient background. On top of the closest centered one stands a man with his hands raised, possibly screaming. At least disgruntled because hovering on platforms above ambiguous figures look down.
There is a preface chapter in italics. It tells of the history of man for the last few hundred years or so. Evidently some time in the "Late Neogene" period (modern day) a virus known as "The Hartian Agent" was brought back to Earth via a space shuttle returning from the third moon of Uranus. (Which alphabetically would be Bianca, just read up on it). This virus set off a chain reaction that led to the disintegration of the substance "papyr". Thus civilisation, or more accurately "papyrocracy", came to an end and The Chaotic Period began. However all was not lost, powerful people in a land known as "Ammer-Ka" had built an isolated bunker staffed with personnel somewhere in the mountains as the last stronghold. It was known as "The Building".
Our hero, the nameless protagonist, stumbles between offices in vain search of the special mission debriefings "a fat officer" stole from him. He participates in surreal events, involving the few side characters who seem as lost as he himself is. A big part of the book are his mind's cross examinations of the recent events. His sole means of refuge is a bathroom where he leaves his memoirs to be found by later generations. He learns of "The Antibuilding" and double, triple, quadruple or even quintuple agents. You shold get the point half way through it.
I liked it. It was kafkaesque and Lem has an extensive vocabulary.