A party was held on a deserted island in the open sea. Numerous celebrities were invited. While most of the guests departed the same day, some opted to spend the night at the mansion on the island. Among them was someone harboring a certain determination. The next morning, upon waking up, the master of the mansion was found murdered in his room. Standing before the corpse was a suspicious-looking butler. Yet, it didn't seem like he was the one who killed the master. "This is a letter left by the culprit near the body," said the butler as he unfolded and read aloud the letter. 'This is just the beginning. You sinful family's members, I will exterminate all of you.' The invited guests were shaken. The butler folded the letter and continued to survey the people. "Actually, I know who the culprit is. The culprit has mingled among the guests here. However, I can't reveal the identity because the master of this mansion, whom I served, was nothing but an atrocious man with connections to a dark organization, having built his position by taking the precious lives of many. He was, in a sense, a heinous criminal. That's why I can understand the feelings of the culprit quite well. Yet, simply supporting the culprit might not be the wisest choice. Therefore, everyone, I want to play a game with all of you." The butler continued speaking. "If anyone among you can identify the 'culprit' who killed the master and the 'weapon' used for the murder, I will provide an opportunity for accusation in the evening. Please accuse the individual to me at that time if you're confident. If the accusation is correct, as a reward, I will use this gun to execute the person who killed the master. And then, I'll arrange for all guests to be sent by cruiser to the nearest port." Is this just a safe game to catch the culprit without causing harm to anyone? With a cruel smirk, the butler continued speaking. "However, if there's a mistake in identifying either the culprit or the weapon, I'll execute that person as a penalty." It was something that betrayed the expectations of the people. "Also, I'll inform the culprit. If you succeed in killing every member of the family, as a celebration, I'll assist your escape using this cruiser. In that case, the remaining guests will be left stranded on this deserted island." Abandoned on such an island, it would undoubtedly lead to starvation. "Therefore, the deadline is the morning of X day. If the deadline is crossed, I'll leave all of you stranded on this island, so please be aware of that in advance." No one dared to oppose the butler's gun. Fear filled the faces of the people. "'The murderer is among you.' Well then, everyone, let the game begin!" Now, the battle for survival between the family and the murderer begins!