On July 2, 2021, 22-year-old Gabby Petito and her fiance, 23-year-old Brian Laundrie took off on the adventure of a lifetime. Driving cross country on a "vanlife" adventure that Gabby shared with the world via her instagram account. By late August, Gabby stopped communicating with her family. And then on September 2, Brian returned home without Gabby. AND HE REFUSED TO SPEAK WITH AUTHORITIES OR HELP IN THE SEARH EVEN AFTER GABBY WAS REPORTED MISSING. It would take weeks to find Gabby's body. And then Brian disappeared and is found dead, having taken his own life. So what on Earth happened? Investigators and Gabby's family unlock the mystery.