XY gelöst

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.

Carnival 1988 in Cologne: 24-year-old mother Petra Nohl is celebrating with friends in the Old Town. On her way home, she is brutally attacked and strangled. The perpetrator escapes unidentified.