The narrator, Edgar Allen Poe, is trying to tell the readers why he is not crazy because he murdered a man over his eye that looked like a falcon's eye. "But why will you say that I am man? The disease had sharpened my senses --not destroyed -- not dulled them."
Every night Edgar goes into the old man's room to see if he is sleeping. "And every night, about midnight, I turned the latch of his door and opened it --oh so gently!"
On the seventh night Edgar wen into the old man's room and killed him by flipping the bed on top of him. "In an instant I dragged him to the floor, and pulled the heavy bed over him. "
The poloce come and Edgar tells them he didn't murder anyone and w=then he starts hearing the heart beat of the old man. "It grew --louder --louder! And still the men chatted pleasently, and smiled."
Edgar believes that he can hear the heartbeat of the Old man and he admits to commiting the crime. "Villians! I shrieked, dissemble no more! I admit the deed!"
In my opionion the most suspenseful part is when Edgar hears the Old man's heartbeat and he is going to tell the police. "No, no! They heard! --they suspected! --they knew!"