Derek has been busy reading Infinite Crisis in preparation for this episode.  Brent links in “52”.  As Alexander Luthor’s multiversal petridish explodes it thrusts young Kara Zor-el 1001 years into the future.

With a time jump and a new title, Supergirl and the Legion of Super-heroes burst onto the Metropolis scene.  Only problem is while they remember her from history, she thinks it is all a dream.