A large metal lock clanks against an imposingly tall gate as a guard inserts a key to open the unidentified structure. That clanking sound of padlocks opening and closing is, perhaps, the signature sound of Two Prosecutors. A half-dozen scraggly men enter the vast space behind the gate, looking as though they hadn’t seen a meal or shelter in quite some time. The film notes that the time is 1937, the height of Stalin’s terror.