The renowned psychologist Kelvin, portrayed by Donatas Banionis, is sent to a space station to look into the death of one of three scientists stationed on the surface of an isolated moon. When he gets there, he finds that only two of the original eighty-plus crew members remain at the somewhat dilapidated facility: Snaut, played by Jüri Järvet, and Sartorius, portrayed by Anatoliy Solonitsyn. Their reception is stran…