Horror writer murdered

Letters from a dead man are the key to their downfall. Who are they? They are not just friends, nor even just readers; they are the protagonists of the novel itself. Between secret rooms, moving corpses, and the labyrinths of the past, they find themselves like marionettes, unaware of who manipulates them. The past returns to unveil the present, and secrets become weapons. No one will escape without paying the price. Who is behind these letters? Has the famous horror writer truly returned from the dead? Or is there another sinister force manipulating them?