“Once...We Were Monsters” follows Dr. Austin Lee and a group of those who have changed, a year and a day after the event, as the discuss their stories, their loss, and how to move forward. On December 24, 2022, more than half of humanity spontaneously turned into blood thirsty monsters, proceeded to devour, maim, and destroy everything and every one in their path. Twelve hours later, those who transformed turned to normal with no memory of what happened. More than 2.5 billion people were killed, mostly by those whom they loved.