about ten o'clock
He did not expect it , but he had an idea -- a very faint one -- that he might see Grace . Of course , if he saw her at the window , where she sometimes sat , it would be no more than polite to go in and tell her what the carrier had said about the second letter . When Larry got in front of the Potter house he was disappointed to see that it was in darkness . It was about ten o'clock , and he knew the family was in the habit of retiring early , especially since Mr. Potter 's disappearance . As he strolled past on the other side of the street , looking in vain for a glimmer of light , or the sight of a girlish face against the window pane , he passed into the deep shadow cast by a big tree on which shone an electric arc light in front of the Potter house . The blackness was quite deep , in contrast to the illumination on both sides of the tree , for electric lamps have the property of casting dense shadows . If Larry had been looking straight in front of him perhaps it would not have happened , but he was staring at where Grace lived , and the first thing he knew he had walked full tilt into a man who was hiding in the darkness behind the big tree .