'Kim Seoyoo (31/F)' is a web designer who can read what others are thinking. She helps her friend, detective 'Woo Hyei (31/F)', catch bad guys. Hyei is the only one who knows about Seoyoo's power, so she's called the "Goddess of Insight" at the Seoul Metropolitan Police Agency. But Seoyoo lives a normal life as an average office worker because she knows that reading minds can be dangerous.
Meanwhile, there are a lot of murders happening in the area. The bodies are really messed up, showing that there's probably a psychopath person doing it. Since the police can't figure it out, Hyei asks Seoyoo for help.
Then, a guy named 'Han Jin (30/M)' comes from another country to Seoyoo's company. Seoyoo can't read his thoughts, which is weird because she can read everyone else's. After he arrives, the murders start happening closer to Seoyoo, and she starts getting messages from the killer directly in her head. "Congratulations, Welcome to the game!"
The killer knows about Seoyoo's power and becomes obsessed with her. Can Seoyoo escape from the psychopath person chasing her?