I think the notebook might have invisible ink on so you can't see with the naked eye but you have to use a blacklight to see the words look i know its late for this but i just got Reddit and I've been really excited to share this info if nobody has told you this yet Matthias if you are reading this you to woods and Sam I believe that notebook has a deeper meaning to it than you think when I want to make a secret message I would have used invisible ink so that not only I can see it but others can peep in it I've used it for my diary you only need to use a black light above the book and something should be on it I don't know if this will work but I know it's late and you're probably giving away the notebook I just thought this might be helpful