Direct answer
Objectives follow journal display order. Some depend on your choices; follow the active objective in the game.
Result
While poking around in the forgotten recesses of Kaer Morhen, Geralt happened across an illusory wall. He removed the illusion and behind it found a copy of the tome "Monstrum, or A Portrayal of Witchers." This tract had caused him no end of trouble and he would have tossed it onto the fire at once - if not for the intriguing handwritten note on the first page...
