A New Day in the Old Town - S2-E1
Trivia: The observer quickly crosses the street after the car crash in the beginning of the episode. (00:00:55)
Trivia: The story is set mainly in 1985. During a scene in the other universe, the observers are outside of a cinema which is showing Back to the Future - with Eric Stoltz as the star rather than Michael J Fox. Stoltz was originally hired to play Marty, but was fired after filming started and Fox was brought in to play the role of Marty.