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A toolmaker is found stabbed to death in his apartment. His car, personal belongings, and cash are missing. Initial leads point to the milieu surrounding the Cologne train station.

Near Worms, a mother is found dead in her bathroom. There are no signs of forced entry. Shortly after the crime, the victim's children encounter a stranger outside the front door.

Cologne, 2007: A 24-year-old woman runs a bistro together with her brother. Late at night, she is still finishing up the accounts. The next morning, her brother discovers her dead in the walk-in freezer.