Beware the blackbirds.

It's Halloween in Vermont, winter is coming, and five humans, two dogs, and a cat are a crowd in Mercy Carr's small cabin. She needs more room-and she knows just the place: Grackle Tree Farm, with thirty acres of woods and wetlands and a Victorian manor to die for. They say it's haunted by the ghosts of missing children and lost poets and a murderer or two, but Mercy loves it anyway. Even when Elvis finds a dead body in the library.

There's something about Grackle Tree Farm that people are willing to kill for-and Mercy needs to figure out what before they move in. A coded letter found on the victim points to a hidden treasure that may be worth a fortune-if it's real. She and Captain Thrasher conduct a search of the old place-and end up at the wrong end of a Glock. A masked man shoots Thrasher, and she and Elvis must take him down before he murders them all. Under fire, she and Elvis manage to run the guy off, but not before they are wounded, leaving Thrasher fighting for his life in the hospital, Mercy on crutches, and Elvis on the mend.

Now it's up to Mercy and Troy and the dogs to track down the masked murderer in a county overflowing with leaf peepers, Halloween revelers, and treasure hunters and bring him to justice before he strikes again and the treasure is lost forever, along with the good name of Grackle Tree Farm..