A young man, the narrator, and an old man live in a quite large two-floor house. The young man loves the old man, but the old man is blind in one eye, which the narrator calls a "vulture eye," and that drives the young man insane. After thought, the narrator decides to kill the elder in his sleep.
Seven times the narrator went to the old man's room to find the eye closed. The narrator could not kill the man when the vulture eye was closed. Every morning, the narrator asked the old man how he slept and if he heard any noises, and he always said he slept well and that he heard no noises the last night.
On the eighth night, the old man was awake and the eye open! The narrator heard a very loud heartbeat, so loud he could have sworn the neighbors heard it. He kills the old man by suffocating him with a mattress. The old man lets out a single yelp, then dies. The narrator then cuts up the body and hides it under the floorboards.
Suspenseful Element: The Talk
Some police officers showed up after some reports of a shriek earlier in the night. The narrator invites them in, gives them a tour, and invites them to take a seat. With great cunning, the narrator set his seat right where the old man was dismembered and hidden.
The three have a conversation, and part-way through, the narrator heard something. It was a heartbeat! It got louder and louder, until he thought that the police officers heard it and were mocking him! Because he thought this, he admitted to killing the old man.
I thought the most suspenseful part of the story was when the three people were talking and the narrator started going mad because of the heartbeat.