In today's episode, we’re traveling back to the summer of 2000, when 16-year-old Molly Bish arrived at a quiet pond in rural Massachusetts, ready to begin another day as a lifeguard. Within minutes, she had vanished without a trace. Only her whistle, her sandals, and her towel were left behind. What should have been an ordinary morning turned into one of the largest and longest-running murder investigations in New England history.