If you want to solve the mystery of Nils (and learn B1-level Norwegian), do this instead of hunting for a ghost PDF:

After hours of research across language forums, it is clear that the learners who succeed with The Mystery of Nils are the ones who pay for the ecosystem.

In 2019, a detailed analysis of the document's metadata revealed some interesting facts. According to this analysis, the PDF was created using a relatively old version of Adobe Acrobat (version 9.0) and was last modified on February 2012. These findings have sparked further speculation about the document's origins and purpose.