You changed trains at the border of Finland and Russia and actually we took sleeping compartments - each buying the entire thing so there was room and privacy and a food service/bar service in each car. It reminded me of the train in Young Frankenstein.
After changing at the border, about an hour later - around midnight local time - we stopped at a town called Vyborgskiy Rayon. It was in the forbidden zone at that time and was really part of the region that was a big to-do in the Finnish/Soviet war - Karelia and east. I got off the train to go in the station where they had what passed for a duty free shop to buy Western Scotch to give to my business partners in Moscow. It was very late, cold, and the streets were lit by single bulb concentration camp lights - no kidding. Wondering around it seemed very Finnish in feel and texture and indeed it was but we had no idea where we were at that time of night and nothing was marked.
I remembered this morning when I heard a piece of music called the Karelia Suite by the Finnish composer Sibelius.