[BEGIN Intertemporal Message]

The tunnels are changing, confounding my attempts to create reliable maps.  Our confirmed path to the renaissance via 2025 no longer exists, and a new doorway has opened connecting 1963 with 1920.  I haven’t been able to identify any patterns to predict their changes, however it is possible to measure their stability.  Travelling through stable tunnels offers a much higher likelihood of a return trip.

[END Intertemporal Message]