Eighteen years ago, FBI Agent Darcy Hunt’s life changed forever when her little sister was abducted right under her nose—murdered by a crazed guild of misguided zealots.

Martha Ratliff conceded long ago that she’d likely spend her life alone. She was fine with it, happy with her solo existence, stimulated by her work as a librarian in Maine. But then she met Alan, a charming and sweet-natured salesman whose job took him on the road for half the year. When he asked her to marry him, she said yes, even though he still felt a little bit like a stranger.

Hen and her husband, Lloyd, have settled into a quiet life in a new house outside of Boston, Massachusetts. Hen (short for Henrietta) is an illustrator and works out of a studio nearby and has found the right meds to control her bipolar disorder. Finally, she’s found some stability and peace. But when they meet the neighbors next door, that calm begins to erode as she spots a familiar object displayed on the husband’s office shelf. The sports trophy looks exactly like one that went missing from the home of a young man who was killed two years ago.

Years ago, bookseller and mystery aficionado Malcolm Kershaw compiled a list of the genre’s most unsolvable murders, those that are almost impossible to crack - which he titled "Eight Perfect Murders". But no one is more surprised than Mal, now the owner of the Old Devils Bookstore in Boston, when an FBI agent comes knocking on his door one snowy day in February. She’s looking for information about a series of unsolved murders that look eerily similar to the killings on Mal’s old list. And the FBI agent isn’t the only one interested in this bookseller.

Lou is a happily married mother of an adorable toddler. She’s also the victim of a local serial killer. Recently brought back to life and returned to her grieving family by a government project, she is grateful for this second chance. But as the new Lou re-adapts to her old routines, and as she bonds with other female victims, she realizes that disturbing questions remain about what exactly preceded her death and how much she can really trust those around her.