In the messages-from-the-stars tradition of such as Hoyle's A for Andromeda and Varley's The Ophiuchi Hotline: a fictional memoir, less a novel than an extended lecture, with Leto simultaneously at his thoughtfully provocative best and irritably didactic worst. Math professor Peter Hogarth, the formidably dry narrator, is called to Nevada's "His Master's Voice" project to help analyze a seemingly modulated burst of neutrino emissions from space. Surrounded by military paranoia and scientific jealousies, Hogarth demonstrates that HMV is indeed a message--but one from an ancient, highly advanced culture, addressed to civilizations developed far beyond Earth's, and involving the message's actual ability (via neutrino beam) to create primordial matter: one tiny message fragment, decoded, yields "Frog Eggs," a pseudo-living jelly that sustains itself by means of nuclear reactions. But the message's real meaning remains a mystery. And Hogarth, convinced of the Senders' benevolence, reasons that the message must be designed so that primitive cultures like Earth's will be unable to misconstrue it and, out of ignorance or malice, create (as the Pentagon hopes) terrible new weapons--a faith that is shaken when further studies of Frog Eggs reveal just such a horrifying possibility. The rewards here are Lem's absorbing, profound analyses of the message--its purpose, its interpretation. The scientific-military-political struggles that accompany them, however, often come across as mere academic hectoring--sometimes incisive, often arbitrary or banal in the anti-West rhetoric. Complex, extremely demanding work altogether (originally published in Polish in 1968), only for alert and determined readers.