A group of former members of the Gestapo participates in espionage activities, helped by a group of locals, dissatisfied with the new authorities. However, members of the Yugoslav secret police, the infamous UDBA, are on their track. This is the first Yugoslavian spy film.

Milan leaves his home and joins the "youth brigade", a group of young people who worked on a railway track. Tragedy strikes when Milan is injured operating one of the mechanical drills that make the building of tunnels possible. But his dedication is greater than his pain, and so he rushes back to the building site instead of staying in the hospital so that he can help the brigade meet the deadline for the completion of the tunnel.

Story of Yugoslav prisoners of war in Germany during Second World War. Based on the novel “Farewell in October” by Oto Bihalji-Merin.