THE OAK TREE that brained my cousin Vince was in good health. It showed no outward signs of illness or decay; the ground beneath it was sturdy and dry. But on that windless, rainless day, it fell over in Aunt Myra's driveway, flattening Vince's goldenrod VW just as he climbed into the driver-side door.

The rest of the family dismissed Myra's insistence that it was "the girl," shrugging it off as simple, grief-stricken hysteria. The girl—a young and particularly small child, she said, who had been abused and possibly killed somewhere inside the 19th-century farmhouse—had become a recent obsession. Myra had even determined a name for her.

"She likes being called Mattie, although I think it's a nickname, short for something else," she told us.

I couldn't keep from staring at the black, earth-choked roots of the tree, ripped out from the dirt and exhumed like bones. The roots looked cold and angry, as did the violent, broken ground they came from. If Vince was a victim of some sort of supernatural, murderous act, it seemed clear to me that the oak tree was just as much of a victim.

I will submit that there were some unusual things about the farmhouse. When Myra and Uncle Lars cashed in their blue chips and bought the place, the dirt-floor cellar was lined with ancient jars, covered in must and webs. Inside were blackened, wizened shapes—or, more alarmingly, nothing at all except a faint, shadowy stain of what might have once been before melting away entirely. Each of the jars was solidly rusted shut. When Lars smashed one open, Myra told us she felt a vigorous chill enter the room. She made him promise not to break any more.

And there was the unused bedroom, at the top of the attic staircase. By the time I moved in with Myra—to help her out with the garden and the dogs after Lars passed—the room had been sealed for over a decade. "It's full of bats," was all she would tell me. "Open the door and you'll let them into the house."

Most days, the place was idyllic. Across the field, the winding stream doubled back on itself in such a way that we could go tubing in the late summer, once the water had lost its mountain chill. In the winter, we'd snowshoe down to the covered bridge and look for fresh animal tracks. And in spring, the fragrances hung in the air, drowsy, full of ripe promise and warmer days to come.

It was a crisp, bright morning when the tree came down on Vince. He had brought Totem—the gargantuan Rottweiler mix that seemed to me at least one-half again as big as an ordinary Rottweiler—to run with the dogs for a weekend while he got over his latest breakup. It had been his fault, and he was in no particular mood to indulge Myra's continuing stories of Mattie and the ills that had befallen the theoretical girl more than a century ago. "You're out of your mind, Mom," he had laughed, cruelly and impatiently after dinner. "You've been this way since Dad died."

At the time, I laughed with him. But as I looked at the smashed driver-side mirror, sheared off and tossed a few feet from Vince's car, I couldn't help but feel as if some sort of punishment had been meted out. Apart from Totem's frantic, inconsolable barking and my own heart pounding, the air was dead quiet. Not a tree groaned; not a leaf rustled. Then I heard the oily creak from the screen door as Myra walked back into the house.