Xu Wende, Caijie and Shijie are colleagues in the same company. At first, Shijie showed concern for Caijie, but Caijie remained indifferent to him.

The relationship between Caijie and Xu Wende seems close, but Shijie feels jealous and suspicious of their relationship. While colleagues were out for lunch, Shijie sneaked into the office and began behaving erratically towards Caijie, including going through her personal belongings and mobile phone. He discovered the chat records of Caijie and Xu Wende, which made his jealousy and doubts intensify.

At this time, he began to plan a terrible operation, intending to murder Xu Wende. Shijie's plan included assaulting Xu Wende on the stairs of the parking lot. He threatens Xu Wende, but Xu Wende deftly distracts him and manages to get back the scissors. However, Shijie pretended to pass out, and when Xu Wende stepped forward to check, Shijie attacked him again and buried him in what looked like a dump.

After completing the horrific operation, Shijie used Xu Wende's cell phone to send a message to Caijie, trying to convince her that Xu Wende had left her. However, when Shijie regrets his actions, he looks at Xu Wende's remains, feeling guilty and confused.

Shijie eventually approached Caijie, but she was extremely angry at his behavior and told Shijie to sue him. In extreme madness, Shijie took out the scissors and attacked Caijie and took out her heart, ending the story in an extremely horrific way. 

"Heart Thief" delves into the relationship between love, jealousy, and insanity, and reveals the dark side of human nature in a thrilling atmosphere. This microfilm brings the audience into a twisted and creepy spiritual world, triggering the audience's reflection on love and madness.