A private, full of emotion story of an engineer Hans F. who arrived on a business trip to USSR on the eve of World War II (spring of 1941). The plot is based on the real life events of pre-war period, on the memories of its direct participants. The film represents a little known blank spot of European history when soon after signing the Molotov-Ribbentrop pact, a short period of friendship, close collaboration and exchange of specialists started between USSR and Germany - before these two countries confronted each other in the mortal combat.