Sorry, I believe that's our fault. For some reason we had forgotten this voiceover in the video, and it remained in Russian. Most likely that happened due to it being the only voiceover that occurs in the video and not in the game itself (other videos don't have any voice). The text says something like "We hoped he'll make it, but he failed to get prepared, and the plague had him," which is quite vague but, on the other hand, makes it quite obvious that it is you who did something wrong. Nevertheless, many players are still confused when they get this out of the dark.
Make sure to look at the task list; finished tasks should have an entry starting with three dots. Now and then it may not mean you have completed it properly, but at least this means you've gained some certain result. In some cases you may also fail your task, often after a really bad choice in a dialogue in the lines of "Gosh, I've had enough. Do it youself, man." Then you usually get a final entry "Oh, somehow it seems I couldn't help him"

or like that.
I believe you won't need any more help if you finished Burakh's day 1 (it starts out pretty tough + the translation is far from being unintelligible). Still, if many problems arise, you may use our official walkthrough:
http://www.pathologic-game.com/path_walkthrough_eng.pdf . It's written mainly without any additional info, just pointing out where to go and what to do for each quest - maybe with some advice. So you won't get spolers unless you read ahead of your actual progress.