Saki, a lawyer, gets into a waiting cab to go to the airport. But the driver of the cab was her sister Satomi, who had been waiting for her, and against her sister's wishes, drove her to the hospital where her mother was in critical condition.
Police Officer So-Eun takes part in the investigation and acts as stand-in for a kidnapped child's mother. So-Eun receives a shocking phone call. Meanwhile, Hye-Jin is a mysterious person, who knows a hidden secret behind the cases.