Sergey Pavlovich Nikitin, a young paleontologist, excavates a dinosaur cemetery in the south of the USSR. Already at the end of the expedition, an unusual phenomenon occurs - in front of many people in a small mountain valley with a lake of petrified resin, a dinosaur ghost appears. The scientist finds out that this is a manifestation of a rare photographic effect of the area and begins to look for an opportunity to obtain such images artificially.