A group of scientists monitoring weather events found gravitational anomalies on scanners from a satellite. It happened on an island in Iceland.   Periodically, the earth's magnetic field was amplified several times, concentrating at one point, creating a strong attraction. But there were times when weightlessness formed on the contrary.   Researchers set up a camp near the nearest settlement and went to the sites of anomalies to collect data.   Nothing boded trouble. Two partners, Tom Frost and Sam Stone went on the next exit, to install equipment for receiving data and collecting video materials. But suddenly, approaching the scene, huge creatures appear on their way. Lurking in the fog, they clearly did not want to be seen. The giants lacked the organs of touch, as if someone had controlled them from outside. Like puppets.    Guests from other worlds? Why are they here? Sam and Tom decided not to ask these questions. They pressed the full throttle and tried to shoot at least some evidence of what had happened, so that they would not be taken to a psychiatric clinic, in case they manage to escape alive from the terrible monsters