The Element of Fear

In an airtight secret room in the suburbs, the light is so weak that it can hardly form a straight line. A man and woman were unconscious on the ground, and the man had a knife inserted into his abdomen... The woman woke up first and found that the door was locked. She found a door key on the ground outside the door through the crack in the door, but she could not pull the door key back. The man finally woke up. He felt pain and fear. During the conversation, they discovered that each other had also lost their memory! This made the suspicion between the two people unabated. The air in the secret room became less and less, and the woman gradually lost her mind. She decided to pull out the knife from the man's body and retrieve the door key. She succeeded! The two of them left the room in opposite directions, walking slowly. Later, the man discovered that he was the target of being kidnapped! He even found the body of a young woman on the ground. He remembered that she was his girlfriend. The man regained most of his memory. He pointedly pointed out that the woman was the kidnapper. Was the woman really the kidnapper?