In 1994, ten-year-old Ethan Marsh and his best friend, Billy Barringer, are camping in Ethan’s backyard when Billy mysteriously disappears overnight. Despite a widespread investigation, Billy is never found, leaving the community haunted by the loss. Thirty years later, Ethan, now suffering from insomnia and unresolved trauma, returns to his childhood home on Hemlock Circle. Soon, strange things start happening—lights flicker on at night, a baseball (Billy’s old signal) appears in his yard, and Ethan becomes convinced someone is trying to send him a message. As he reconnects with former neighbors and investigates the night Billy vanished, Ethan’s search leads him to the long-abandoned Hawthorne Institute in the nearby woods. He discovers that many of the eerie events were orchestrated by Billy’s younger brother, Andy, in a desperate attempt to uncover the truth. Ultimately, Ethan learns that Billy’s death wasn’t due to an abduction. That night, Billy left the tent and was accidentally struck and killed by Ashley, Ethan’s teenage babysitter, who was driving drunk. Terrified, Ashley covered up the accident, hiding Billy’s body near the waterfall. The revelation leads to Ashley’s arrest and some closure for the community. A year later, Ethan becomes guardian to Ashley’s son, and finally begins to heal from the tragedy that shaped his life.