[1] The novel is written as a first-person narrative, the memoir of a mathematician named Peter Hogarth, who becomes involved in a Pentagon-directed project (code-named "His Master's Voice", or HMV for short[2]) somewhere in the Nevada desert, where scientists are working to decode what seems to be a message from outer space (specifically, a neutrino signal from the Canis Minor constellation).

Throughout the book Hogarth—or rather, Lem himself—exposes the reader to many debates merging cosmology and philosophy: from discussions of epistemology, systems theory, information theory and probability, through the idea of evolutionary biology and the possible form and motives of extraterrestrial intelligence, with digressions about ethics in military-sponsored research, to the limitations of human science constrained by the human nature subconsciously projecting itself into the analysis of any unknown subject.

Two variations had been created: a viscous liquid nicknamed "Frog Eggs", and a more solid version that looks like a slab of red meat called "Lord of the Flies" (named for its strange agitating effect on insects brought into proximity with it).

"Frog eggs" seems to enable a teleportation of an atomic blast at the speed of light to a remote location, which would make deterrence impossible.

By the time the project is ended, they are no more sure than they were in the beginning about whether the signal was a message from intelligent beings that humanity failed to decipher, or a poorly understood natural phenomenon.

Dave Langford reviewed His Master's Voice for White Dwarf #49, and stated that "Lem offers a sheaf of cosmic answers, some truly mindblowing – but it isn't easy reading.

[citation needed] Głos Pana was translated from Polish into Chinese, Czech, English, Finnish, French, Georgian, German, Hungarian, Italian, Japanese, Latvian, Portuguese, Romanian, Russian, Serbian, Slovak, Slovenian and Spanish.