Liu Yu searched for work everywhere but failed due to her low educational qualifications, adding to her “sense of crisis”. At the same time, she also felt the relationship between Wang and her was not as strong as before, and gradually developed a pessimistic outlook. As a result, Liu Yu purchased sleeping pills and a fruit knife, preparing to commit suicide, but upon thinking of Wang whom she deeply loved and being reluctant to part with him, she instead asked Wang to meet her at a hotel. After they met that night, Liu Yu secretly placed 40 tablets of sleeping pills into the coffee she had prepared for Wang to drink. After Wang feel asleep, the idea of dying together with Wang suddenly came to Liu Yu. So, she put on her clothes, retrieved the knife from her bag, aimed it at Wang, and stabbed him. After killing her boyfriend, Liu Yu again went out to buy sleeping pills, planning to commit suicide, but was arrested by the police.