Winter has arrived in Broward's Rock, South Carolina, and business has slowed for Annie Darling, owner of mystery bookstore Death on Demand. So when the island's resident writer publishes the latest in her popular mystery series, Annie jumps at the chance to host a book signing, even though it conflicts with her shift at the local charity shop, Better Tomorrow.

Luckily, fellow volunteer Gretchen Burkholt agrees to sub for her. The signing goes well, but Gretchen interrupts the event multiple times, leaving voice mails about scandalous news she's dying to share. Even though Gretchen tends to be excitable, Annie heads over to Better Tomorrow, where she finds Gretchen dead on the floor, an axe by her side.

Annie enlists the help of her husband, Max, to piece together a puzzle involving an overturned kayak, a stolen motorboat, a troubled love affair, and a reckless teenager. And she must tread carefully in her investigation, because a killer is on the loose, and that killer works well in the foggy days of winter...