Shadows over Yalta

September 1950. Night train Moscow—Simferopol.
In cabin number six, blood is dripping onto a sleeping woman. On the upper bunk lies the corpse of an unknown man, stabbed with three precise strikes. Instead of a hunchbacked old man in glasses and a straw hat, there is now a corpse without any documents. The old man's belongings have disappeared. Only one strange clue remains: