From Sarah Pekkanen, the New York Times bestselling author of House of Glass and co-author of The Wife Between Us—a stunning new novel of buried secrets, mind-bending history, and one woman’s search for the truth . . .

Decades ago, four women at prestigious Marquis University were the focus of parapsychology experiments led by a pioneering researcher. Just as they seemed on the verge of a real breakthrough, the four women vanished and the program was abruptly shut down.

In the present day, Riley Bell is desperate for a new life when she lands a caretaker job for Betty Sadler—an elderly, wheelchair bound woman whose house seems suspended in time. No television. No microwave. And Betty has never even heard of a cell phone.

Newly widowed, Betty discovers notes in her late husband’s papers that spark her quest to answer one final unanswered mystery that has shadowed her for six decades: what happened to her three best friends who disappeared on the same day?

Told in dual timelines, as Betty’s world of 5 o’clock martinis and increasingly rigorous experiments converges with Riley’s present-day search for the other three women, the danger and intensity grow white hot.

Because whatever was swirling around these four exceptional young women is rising again.