假面山庄

As in previous summers, Morisaki and his wife invited friends and relatives to spend a holiday in their villa. Unexpectedly, the peace was broken in the second morning and two men with guns broke into the villa and kidnapped the eight persons on the scene. They tried to save themselves: wrote a SOS within the extremely short period of time and controlled the switch with a timer to create a short circuit. However, they failed due to someone's tricks. In the third morning, a hostage was found dead in the blood and the kidnappers could not be the murderer. They realized that someone hidden among them was more terrible than the kidnappers.