The film is portrayed in a war backdrop were USSR occupied the Poland.
This below synopsis i got it from IMDB:
On 17 September 1939, a group of Polish officers and soldiers are imprisoned by the Soviet Army on the border of Poland. Anna and her daughter Nika travel from Krakow to meet her husband and officer Andrzej and they try to convince him to leave the soldiers and escape back home. However, Andrzej refuses to leave the troop and is deported to USSR. Later the Soviet tells that the Polish officers had been massacred by the Germans in the Katyn Forest with a shot on the back of the neck. However Anna retrieves Andrzej’s diary and discloses that the soldiers had been actually murdered by the Soviet Army.
I am very impressed on the story telling with out any busyness, but the content stays in you by the affected people and their day to day living conditions.
Some of the Shocking real facts were..
The number of victims is estimated at about 22,000, with a lower bound of confirmed dead of 21,768. According to Soviet documents declassified in 1990, 21,857 Polish internees and prisoners were executed after 3 April 1940: 14,552 prisoners of war (most or all of them from the three camps) and 7,305 prisoners in western parts of the Belarusian and Ukrainian SSRs.[b] Of them 4,421 were from Kozelsk, 3,820 from Starobelsk, 6,311 from Ostashkov, and 7,305 from Belarusian and Ukrainian prisons.[b] Head of the NKVD POW department, Maj. General P.K. Soprunenko, organized “selections” of Polish officers to be massacred at Katyn and elsewhere.
The Katyn massacre, also known as the Katyn Forest massacre (Polish: zbrodnia katyńska, mord katyński, ‘Katyń crime’; Russian: Катынский расстрел Katynskij ra’sstrel ‘Katyn shooting’), was a mass execution of Polish nationals carried out by the People’s Commissariat for Internal Affairs (NKVD), the Soviet secret police, in April and May 1940. The massacre was prompted by Lavrentiy Beria’s proposal to execute all members of the Polish Officer Corps, dated 5 March 1940. This official document was approved and signed by the Soviet Politburo, including its leader, Joseph Stalin. The number of victims is estimated at about 22,000, with 21,768 being a lower bound. The victims were murdered in the Katyn Forest in Russia, the Kalinin and Kharkiv prisons and elsewhere. Of the total killed, about 8,000 were officers taken prisoner during the 1939 Soviet invasion of Poland, another 6,000 were police officers, with the rest being Polish intelligentsia arrested for allegedly being “intelligence agents, gendarmes, landowners, saboteurs, factory owners, lawyers, officials and priests.”