A team of Soviet scientists is air-dropped onto the Siberian plateau to hunt for diamond veins. Joining leader Sabinin (Smoktunovsky) are fellow geologists Sergei (Urbansky), Andrei (Livanov), and Tanya (Samoylova). After weeks of arduous work, their mission is a success, but then forest fires threaten their safety. Next, radio communication with Moscow is lost. Isolated in a remote and unforgiving terrain, the team ponders their own mortality and prospects for survival.

Kalatozov's collaboration with cinematographer Sergei Urusevsky produced several classics, not least among them this deep and stunning work. Pioneers of handheld camerawork, here they contrast extreme close-ups with deep focus shots of the Siberian landscape. Branches and flames seem to touch the lens as the camera urgently moves around the actors. “Letter" portrays the Soviet ideals of heroic deeds and individual sacrifice for the greater good, but its suspenseful storyline and stark, arresting shooting style transcend propaganda. Among Kalatozov's lesser known films, this diamond deserves to be discovered.