read the excerpt from the adventure of the mysterious picture. all this was half muttered to myself, as i hastily slipped on my clothes; which having done, i groped my way out of the room, and down-stairs to the drawing-room. here, after tumbling over two or three pieces of furniture, i made out to reach a sofa, and stretching myself upon it determined to bivouac there for the night. what technique does irving use to build suspense in the excerpt?