In the summer of 2021, a young couple's idyllic cross-country "van life" adventure, documented for thousands of online followers, came to an abrupt and silent end. When Gabby Petito was reported missing and her fiancé returned home without her, the internet transformed from a passive audience into an unprecedented investigative force. This is the story of a murder that was solved not just by detectives, but by a global community of digital sleuths who dissected every post, pixel, and geotag to uncover the truth hidden in plain sight.