Naushki is the border crossing point between Mongolia and Russia - a process which took over five hours late in the evening, thus, no images (customs checking with dogs, searches through all the carriage infrastructure, knocking on the panels, looking under the seats etc.) - quite a thorough check.
By contrast, the authorities never even looked at us when we left the country, passing into Belarus!
From here we continued on through Ulan-Ude (the meeting point with the Trans-Siberia train from the east, Vladivostok), Slyudyanka, Irkutsk, Krasnoyarsk, Novosibirsk, Omsk, Tumen, Sverdlovsk (Ekaterinburg), Permi, Kirov, Gorky, Vladimir and Moscow.
And all the time trying to learn the Russian Cyrillic alphabet!
Winston Churchill in a broadacst in October 1939 said: "Russia is a riddle wrapped in a mystery inside an enigma."