In the late 1950's, at the height of the Cold War, the white sandy beaches of Latvia were part of the Soviet Union's frontier, well guarded and well defended. Every night, Soviet tractors would comb Latvia's coast and leave fine grooves in the sand. Trespassers of any kind (spies, defectors, invaders) who might cross the beach would leave telltale tracks and lead Soviet patrols to investigate. One morning, three Soviet patrolmen discover a woman's shoe in the sand and footsteps leading to the local village of Liepaja. Alarms sound, troops are dispatched: an official inquiry begins. To whom does the shoe belong? What suspicious activities are taking place? Is there a newcomer in town? A three man investigative team along with their well trained dog are determined to find the shoe's owner and her motives for being on a forbidden beach at night. But things don't go well. Despite their military training, the patrolmen can't solve the mystery. Liepaja has seductive power. The residents, their habits and customs distract the investigators.