The anesthetist Sina Seibold is attacked and fatally injured in front of the clinic where she works. Because of her commitment to euthanasia, she had previously been subjected to hostilities on several occasions. Pensioner Peter Menk was among those who were critical of her. His wife had Seibold accompany her to her death. A video shows him angrily insulting the doctor. Inspector Vera Lanz, however, doubts that the elderly gentleman is capable of murder.