had, perhaps, even looked from the doorway, as she had fancied. She trembled as if at the presence of a ghost, and feared to see him.
But where was he? Must she look in every nook and corner? Should she call him out loud? Hungry for him as she was, she could not yet do that; her heart beat too fast. Yet she longed to tear the mystery open and let in the light again—the old-fashioned sunlight of his actual visible presence—and break into tears on his shoulder. She moved across the room on tiptoe now, as if she were guilty of some crime in being there, threw herself on the divan, and tried to think it out.
As she calmed herself, the thought of the book she had replaced on the shelf came to her, and she ran across the studio to take it from its shelf. It fell open of itself to The Purloined Letter, and she smiled to herself. That proved her hypothesis to be right. Was not the purloined letter concealed in plain sight, so prominently placed that it escaped the search? Then Astro's hiding-place would be as obvious, if she reasoned aright. Could she solve that as she had solved the other, by her intuitions, by means of his black light?
Black light! The very words were enough to tell her. Where should he be, but in the dark room where she first witnessed his experiment, where the little phosphorescent Buddha, though invisible in the dark, still radiated its mysterious waves of energy?
So it was solved! She hugged herself with delight, and smiled at the prettiness of his plans. How well he
