In April of 1992, a 24-year-old woman headed in to a night shift at work in Massachusetts. But when her co-worker arrived the next morning, she noticed a few unsettling things: Her car was still in the parking lot, the door was unlocked, and the OPEN sign was still on. When the woman’s body was found in the woods, police persevered to find her killer. And thanks to a shocking letter, they’d get their answer. This is the story of Lisa Ziegert.