Tell about Dr. Armstrong’s dream at the beginning of Chapter Six.

Dr. Armstrong has a dream that he is in the operating room, standing over the woman he killed because he was drunk. When the nurse pulls back the sheet, he sees Emily Brent laying in her place. Emily says, “In the midst of life we are in death.” The nurse then places a handkerchief over the patient’s face and when she pulls it off again, Dr. Armstrong sees Anthony Marston. Marston is purple, convulsing and laughing. Then Armstrong wakes up to a new morning.