Scientists are still looking for a planet to be the new home of mankind, but the discovered planets are not feasible from a transportation standpoint. The discovery of stone discs with inscriptions in a long-lost language, on Earth and for a month in space, supposed to be a means of transport, gives birth to new hopes. A team of infantrymen is sent to guard the research unit of that month, as a punishment for failure in a previous mission. Their arrival coincides with the first experiments made on discs, experiments that do not go as expected, the basis being invaded by a species of aliens whose sole purpose is to eradicate the human race.