The narrator hears a noise coming from beneath the floorboards that only he can hear. He becomes increasingly paranoid and distressed by the noise, which he realizes is the beating heart of the man he murdered and hid under the floor. He had dismembered and concealed the body there after killing the man, but the heart continues to beat loudly, audibly to the narrator alone. He struggles to maintain his composure in front of the police officers he has invited into the home, but eventually shouts for them to tear up the floorboards, admitting to the murder.