A old notebook with a leather cover featuring the Triquetra, the time traveler's symbol. Inside are handwritten entries, sketches, and diagrams that document Winden's fate. Various events from the past and future are noted up until November 12th, 2019, after which several pages are torn out.
The older, time-traveling Claudia Tiedemann carries the notebook with her. She leaves it with Peter Doppler and Tronte Nielsen on the night of November 4th, when they find Mads Nielsen's body in the bunker.