Lightning splits the sky as I grab my Maglite and take the sidewalk to the back door. On the porch, crime scene tape flutters in the wind. The bloodstains are still there, but I know they’ll soon be washed away by the rain. Ducking under the tape, I use the key and step inside.

The smell of death lingers. I shine my light around the kitchen. Smudges of gray-black soot from the fingerprint powder cover the countertops, the cabinets, the table and the sink. Several drawers stand partially open. Someone tracked mud onto a braided rug. I think of Bonnie Plank, and I wonder how many times she scolded her children for the same offense.

Outside, thunder rumbles with enough gusto to rattle the windows. Inside, the house is as still and silent as an underwater cave. I know this isn’t the ideal time for a look around, after dark, when I can’t see shit. But I know more about the Plank family now. Specifically, I know more about Mary. A young girl with a big secret and a host of problems that secret would have brought down on her life. That’s when I realize her bedroom is the room I want to search again.

Standing in the darkened kitchen, I think about what might have happened the night of the murders. Had it been dark like this when the killer arrived? Had the Plank family already turned in for the night? Or had the house been lit with the glow of lantern light? Since most dairy operators rise as early as four A.M., they go to bed early.

“The Planks were in bed,” I say aloud.

The mind of a killer is a dark, malignant place, viscous with a cancer of black thoughts and secret hungers most people can’t imagine. A place most people don’t want to conceive of because they’d never see the world in the same light. Getting inside a place like that is akin to climbing into a crypt and snuggling up with a decaying body. Still, I open that door and step inside. I conjure thoughts I hope will tell me who and why and how.

Lightning flashes, illuminating the kitchen for a split second. I shine my beam on the back door and wonder where the killer entered. There was no sign of forced entry. Did the Planks lock their doors? Or did someone let him in? Someone who knew him?

The killer enters through the unlocked back door. He’s got a gun and a flashlight. He carries a coil of speaker wire in his pocket. He wears gloves. All of it shows intent, premeditation. He’s scared, but driven—and excited. He knows what he wants, what he must do. He wishes for light, but compensates for the lack of it. Is he alone?