Hi t-p
I don't even know the plot or the period it was written in.
Ah, but you do... it's Записки из Мертвего Дома in Russian - the libretto is taken from episodes in Dostoevsky's "book". (Of course, in reality it was not a "book", but appeared as a sequence of magazine articles originally - it was only printed in book form much later).
It's really an amazing work, I completely agree with Opilec here. Probably the most remarkable thing is that there is no "story", and there are no "main characters"... it is just a sequence of episodes in the life of the prison-camp. As a kind of "linking theme" we see Alexander Petrovich Goryanchikov (who is symbolically "Dostoevsky" in the story, he's the "political prisoner from St Petersburg") arrive in the prison, befriend the illiterate Dagestani boy Alyeya (I suppose he is really "Ali" in Dagestani) and teach him to read.. and then at the end Goryanchikov is freed due to orders from St Petersburg. The only other character whose story might also run through the opera is Filka Morozov, if it really is him who dies at the end under the name "Luka Kuzmich"... or is it Shishkov's insane delusion that it's his tormentor, Filka?