Read it through once

Meantime the hellish tattoo of the heart increased. It grew quicker and quicker, and louder and louder every instant. The old man's terror must have been extreme! It grew quicker, I say, louder, louder! I felt that I must scream or die! and now — again! — hark! louder! louder! louder! louder! "Villains!" I shrieked, "helpers! — here!" — I threw open the lantern and leaped into the room. He shrieked once — once only. In an instant I dragged him to the floor, and pulled the heavy bed over him. I then smiled gaily, to find the deed so far done.