On March 13, 1997, thousands of people across Arizona reported unusual lights moving through the night sky. Some witnesses described a massive formation passing silently overhead, while later that evening a separate series of bright lights appeared near Phoenix.

This episode examines the two major events that became known collectively as the Phoenix Lights, the military explanation for some of the sightings, and the eyewitness reports that remain more difficult to reconstruct decades later.

Were the Phoenix Lights a combination of military activity and mistaken observations, or did some witnesses see something that has never been conclusively identified?