Years ago, bookseller and mystery aficionado Malcolm Kershaw compiled a list of the genre’s most unsolvable murders --- which he titled “Eight Perfect Murders” --- chosen from among the best of the best. But no one is more surprised than Mal, now the owner of the Old Devils Bookstore in Boston, when an FBI agent comes 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 who spends almost every night at home reading. There is a killer out there, watching his every move --- a diabolical threat who knows way too much about Mal’s personal history, especially the secrets he’s never told anyone, even his recently deceased wife.