The game you're replying on (Serenity Chapter 2) is a separate game from Serenity. So yes you would need to download Serenity Chapter 2 if you don't have it. It is not part of Serenity 1.4 (<<< That is the first chapter of the game and a separate download). You do not need the 'persistent' file unless you reached the end of Serenity 1.4 and still didn't have all of the gallery unlocked.