In Timeless (2016/II), we can see pages that Konstantine wrote by hand. They are from director Alexander Tuschinski's novel "Fetzenleben" that later got turned into this film.
The song "Let's Run Away Like Bonnie and Clyde" that played during the end credits of Timeless plays in the opening credits of Fetzenleben, and its melody is used as a re-occuring musical motif in the film.