Memoirs Found in a Bathtub (a literal translation of the original Polish-language title: Pamiętnik znaleziony w wannie) is a science fiction novel by Polish writer Stanisław Lem, first published in 1961.

The introduction dwells on the difficulties of historical research on the fictional 'Neogene Era', "the period of the heyday of the pre-Chaotic culture, which preceded the Great Decomposition".

One researcher suggested that Pentagon was a kind of military brain, the center in charge of maintaining the faith of Cap-i-Taal, dominant in Ammer-Ka in the period of U-S.

This was confirmed by the finding of the diary, supposedly of an agent trapped deep within the subterranean bowels of the vast Third Pentagon, although the authenticity and authorship of the document were questioned by some researchers.

In a Kafkaesque maelstrom of terrifying bureaucratic confusion and utter insanity, the agent attempts to follow his mission directives, conducting on-the-spot investigations: "Verify.