The Lost Night [Film and TV Commentary]

This film is a remake of the Spanish film "The Mystery of the Female Corpse". The story revolves around a body lost by the National Institute of Scientific Research. The husband (played by Kang Yu) planned a perfect crime to kill his wife (played by Kim Hee Ae), but just a few hours later, his wife's body disappeared from the morgue of Guokesou. At this time, the husband also received a letter "I will wait for you where our secrets are buried." The police suspected that all this was done by the husband, but the husband insisted that it was all directed and performed by his wife. Is she dead?