Poor woman - married to a horses arse with his head in a jar! Running from a wannabe Tsar, who's come from afar, the most evil by far, with his head up his arrrrrrrrrrrrrrr... (..n't going to finish that thought actually! :- ) )
PS: I was about to say something about such serendipitous meetings between key characters in remote locations being lazy writing, but changed my mind: It's the middle of winter so travel is difficult, and Lady Selnikov is a fugitive seeking sanctuary; ERGO: she needs a travelling cathedral to escape in ...or a holy railway! Nice thinking guys!