What did the narrator do to prepare for the eighth night, in Tell-Tale Heart

Edgar Allan Poe’s short story "The Telltale Heart" was published in 1850. Its unreliable narrator -- in an apparent effort to persuade the reader that he is not insane -- recounts his determination to murder “the old man” because he cannot bear the sight of his victim’s cataract-shrouded eye. As evidence of his sanity, the narrator describes his cautious actions on the seven nights leading up to the murder: how over the course of several hours he slowly opened the old man’s door, thrust in his head, and allowed a ray of light from his lantern to fall on the man’s eye. He was waiting, he explains, for his victim to open his eyes, thus goading our narrator into murdering him.

On the eighth night, the narrator goes through this process once again. The thought of the old man’s helplessness seems to give him an extra thrill tonight, because he chuckles, possibly waking the other man up. The room is pitch black. Slowly our narrator opens the door and leans into the room. Again he makes an inadvertent sound, and the old man cries out and sits up. For the following hour, neither our narrator nor his victim moves. The thought of them both waiting -- frozen -- listening -- is one of the creepiest images in the story.

Finally the narrator hears his victim groan in fear. Immediately, he begins to identify with the other man, imagining what his thoughts and feelings have been over the course of the night and relating them to his own anxious experiences in the dark. But this empathy does nothing to deter him from his plans. He opens his lantern, releases a ray of light, and finally sees the sight that has been obsessing him: the other man’s cataract-covered eye. At the same moment, he hears what he believes is his victim’s heart pounding in terror. After listening to it for some time, he attacks the older man and kills him.

This is all that the narrator tells us about his “preparations”. We, as readers, may wonder what he’s leaving out. What tool did he use to dismember the corpse, and where did he get the “tub” in which he somehow managed to contain his victim’s blood? When he describes this process, do you think he’s telling the truth? What else might he have chosen not to tell us, and why?