On the eighth night, the narrator repeated the same routine he had done on the previous seven nights, but he was more careful.
At twelve, he opened the door and slowly let himself in. This night, the old man felt there was someone in his room. The narrator patiently waited, and when he shed light into the old man's eye he saw it open and felt his anger increasing.
As he started to hear the old man's heart beating, his anger turned into fear and quickly moved into his victim, tightly holding the bed covers over him. Just before the murder is consumed, he smiled as he felt he was succeeding.
Then, he carefully hid the body and calmly received the police officers. Because of his behavior, he was able to convince them that the old man was not there, until he started to hear the heart beat again. In the end, he couldn't stand his suffering and confessed his crime.