That is... actually quite the interesting fact. If I recall correctly, our german trailer had something along the lines of must be stopped, and I'd love to add to it, but currently my internet is too bad to play the video. (Or does anyone happen to have the german lines for me?)
For the english translation, I always happened to understand the 'unwritten' as 'erase from history' in the sense of 'this happened but we'll fix it and erase from history that it ever happened'.
EDIT: Purely going by my memory, the first line was 'dieses Unheil, größer noch als die siebte Katastrophe, muss aufgehalten werden.' (second sentence absent from my memory). So, like 'this calamity, greater even than the Seventh Calamity, must be stopped'. Quite on the point, since 'aufhalten' is used for stopping something that is in the process of happening.