Professor Tarantoga saves human civilization! After using his chronopad to investigate the leading scientists and artists in history, Tarantoga concludes that without exception they are lazy drunkards. So naturally, he sends smart young people into various eras to invent differential calculus, to paint the Mona Lisa, etc.—all while a pair of police inspectors have their eye on him.

I’d bet my last złotych that Lem is carefully satirizing the rule of the Polish United Workers’s Party in this story of a fourth-millennium man who hails from Mars and has room in his brain for two or three different personalities (Kazimierz Nowak, Hipperkorn, and possibly a dreaded Nanów), the first of which leapt from a touring chronobus in the 20th century where he hoped to find the inventor of time travel, Professor Tarantoga.