午夜Soo-kyung is a news reporter with a troubled past. Back then when she was a teenager, she and her best friend Min-soo wanted to go to a park, but there Min-soo disappeared without a trace. Soo-kyung felt responsible and decided to become a journalist, to investigate the case on her own. But until now she has found no sign of her friend. One day, she gets a call from her childhood-friend Min-gook who insists that he saw Min-soo. Soo-kyung doesn't believe him at first, but finally she is able to meet Min-soo again. Min-soo in return confirms her identity and also recognizes Soo-kyung, but she behaves totally different. Soo-kyung feels that something is still terribly wrong and everything points to Min-soo's boyfriend Dong-min.