midnight
For a few moments he waited , silent and motionless . It came again , louder than before , and yet in it there was something of caution . It was not the heavy tattoo of one who had come to awaken him on a matter of business . Who could be his midnight visitor ? Softly Howland went back to his heavy coat and slipped his small revolver into his hip pocket . The knock came again . Then he walked to the door , shot back the bolt , and , with his right hand gripping the butt of his pistol , flung it wide open .