midnight
At dinner he was abstracted and silent , and retired to his own apartments . Just off his sleeping room was a smaller one which constituted his laboratory , for Hubert was a man of science in his leisure hours . This room was the one discomfort of poor Mrs. Gray , who feared explosions or electric shocks , and sighed many a time as she heard the door close after the entering form of her son . To-night it closed firmly , and had not opened again before slumber muffled the ears of the apprehensive mother , nor had the light from the single gas burner ceased to throw out its yellow challenge to the mellow , midnight moonlight without . Could Mrs. Gray have looked within , she would have seen Hubert sunk in the depths of a leather covered chair , with his dark , frowning face leaning upon his hand . He was thinking . Something like this was the matter of his thoughts : In this little room questions had been asked and answered .