Travelogue of two film historians Nikolay Izvolov and Sergey Kapterev who visit world film archives around the globe in search of a lost sound version of one famous Soviet cartoon. It's "The Post" made by Mikhail Tsekhanovsky in 1929 and based on a poem by Samuil Marshak. At first "The Post" has been released in a silent form and later Tsekhanovsky remade it with experimental music and narration by Daniil Kharms. At that moment it was the first Soviet sound cartoon and it was a success all over the world. Russian film studies consider "The Post" to be of great importance and artistic value but unfortunately it's still lost. Only the silent version and the 1964 remake are still known and available.