Footprints Led Into the House. None Led Out.

Hinterkaifeck was a lonely farm in Bavaria, in southern Germany, about forty miles north of Munich. In the spring of 1922, six people lived there: the farmer Andreas Gruber, his wife, their widowed daughter, her two young children, and a new maid who had arrived that very day.¹

In the days before the end, strange things happened at Hinterkaifeck.

Andreas Gruber told neighbors he had found footprints in the fresh snow, leading from the forest to the farmhouse. There were no footprints leading away.² He heard footsteps in the attic at night. He found a newspaper in the house that no one in the family had bought. A set of keys went missing.³

The family's previous maid had quit months earlier. She told people the house was haunted. She said she heard noises in the attic.⁴

Andreas Gruber did not call the police. He told neighbors he had searched the attic and found no one.

On the night of March 31, 1922, all six people at Hinterkaifeck were killed.⁵

They were not found for four days. In that time, neighbors noticed smoke rising from the farmhouse chimney. Someone had been feeding the cattle. Someone had eaten food from the kitchen.⁶ Whoever had killed them had stayed. Living in their house. Among the bodies.

The murders have never been solved. More than a hundred suspects were questioned over the years. No one was ever charged.⁷

The farmhouse was torn down in 1923.

Matthias Brandl was a carpenter, and he did not believe in ghosts. He believed in rot, and termites, and bad wiring, which killed far more people.

He was renovating a farmhouse about three miles from where Hinterkaifeck used to stand. It was old, nearly two hundred years old. While pulling up the attic floor, his crowbar hit metal.

A tin box. Wedged between two beams, under a loose board, exactly the kind of place a person would hide something if they lived in an attic and did not want the family below to find it.

Inside was a child's school slate, the kind made of real stone, with a wooden frame. A newspaper from March 1922. And a ring of iron keys, one missing.

He would not have thought anything of it. But the newspaper's front page was from the week of the murders. And scratched into the child's slate, in shaky letters, was a single line.

Footprints in. None out. Do not look up.

He looked it up that night. He read about Hinterkaifeck. He read about the footprints, the attic, the missing keys. He read about the killer who had stayed for days.

Then he read the part that made him put his phone face down on the table.

The youngest victim, a two-year-old boy named Josef, had been found in his cot. The older child, Cäzilia, seven, was found in the barn with the others. Investigators believed she had survived for hours after the attack.⁸

Cäzilia went to school. She would have had a slate.