Haunted by a family history of women dying young, nursing student Sienna Carter has spent her winter term at Loma Linda University studying its celebrated Blue Zone and its promise of a longer life. As the term ends and she considers transferring to Portland, she begins noticing unsettling patterns in campus records and the reassuring language used to explain them. When an unexpected midnight deadline forces Sienna to make her decision, an unnatural hum begins affecting the people around her, turning her final night at Loma Linda into a disturbing struggle to leave.