Footprints lead out of the dark woods, up to the farmhouse door, and stop. None lead away. Days later, an entire family of six lies dead, and the killer has been living among the corpses, feeding the cattle and eating the family's bread.

This deep dive examines the 1922 Hinterkaifeck murders, one of Germany's most infamous unsolved crimes. Beyond the gruesome timeline, it is a study in how social isolation became a death trap and how the limits of early 20th-century rural justice destroyed any chance of a solution.

• The warning signs: a stranger's newspaper, footsteps in the attic, and a maid who fled believing the house was haunted
• How the Grubers' isolation, rooted in a 1915 incest conviction, left them with no one to call for help
• The killer's three days living in the house, and the murder weapon, a mattock, lat ...