From the New York Times bestselling author of The Kind Worth Killing and Eight Perfect Murders comes an inventive, utterly propulsive murder-mystery in reverse, tracing a marriage back in time to uncover the dark secret at its heart.

Thom and Wendy Graves have been married for over twenty-five years. They live in a beautiful Victorian on the north shore of Massachusetts. Wendy is a published poet and Thom teaches English literature at a nearby university. Their son, Jason, is all grown up. All is well…except that Wendy wants to murder her husband.

What happens next has everything to do with what happened before. The story of Wendy and Thom's marriage is told in reverse, moving backward through time to witness key moments from the couple's lives—their fiftieth birthday party, buying their home, Jason's birth, the mysterious death of a work colleague—all painting a portrait of a marriage defined by a single terrible act they plotted together many years ago.

Eventually we learn the details of what Thom and Wendy did in their early twenties, a secret that has kept them bound together through the length of their marriage. But its power over them is fraying, and each of them begins to wonder if they would be better off making sure their spouse carries their secrets to the grave.