Original title: Głos pana.
Twenty-five hundred scientists have been herded into an isolated site in the Nevada desert. A neutrino message of extraterrestrial origin has been received, and, under the surveillance of the Pentagon, the scientists labor on His Master's Voice, the secret program set up to decipher the transmission.
Among them is Peter Hogarth, an eminent mathematician whose posthumous diary makes up the novel. Hogarth joins His Master's Voice after all efforts to decode the message prove futile and, after an early success, gives up on the project to pursue clandestine research into the so-called TX effect. Hogarth comes to realize that the TX effect could lead to the construction of the ultimate weapon - a fission bomb - and that such knowledge must not be allowed into the hands of the military.