“What’s the matter? What is it? Is it a burglar after my rare books?” inquired Dr. Spidderkins, coming suddenly to the window, behind Mr. and Mrs. Sandow. He leaned out, and Tom could see, in the light of an electric arc lamp in front of the house, that the doctor was dressed, and had on his spectacles, as if he had been sitting up reading. “Go back to bed!” called the woman. “I haven’t been to bed. I must have forgotten to go,” answered the doctor. “I was reading an account of how the Romans invaded England. It’s in a very rare first edition of----” The rest of the sentence was cut off, as Mr. Sandow slammed the window down. “They don’t want him to speak to me,” thought Tom. “I wonder what’s the matter with that couple? They seem to want the doctor to do just as they say.” An instant later the window was raised again, and the aged physician looked out. “Did you say some one was stealing my books?” he asked. “Are you a policeman? I’m much obliged to you. I hope the fellow didn’t get my first folio Shakespeare.” “No, I’m not a policeman! No books have been stolen!” cried Tom. “I’m from Townsend’s book store.” “Oh, yes. You’re Theopholus--no--I remember now; you’re Tom Baldwin. Wait; I’ll be right down. Have you some more books for me?” Before the boy could answer, the window was shut again, but in less than a minute the front door opened, and Dr. Spidderkins, holding a candle in his hand, for he liked that old-fashioned method of going about the house after dark, was inviting Tom to enter. The story of the mishap was soon told. “I thought maybe I might have dropped the envelope here,” the boy finished. “Wait a minute!” exclaimed Dr. Spidderkins, as he reached for his pocketbook. He searched hurriedly through it. Then he uttered an exclamation. “There! It’s all my fault. I knew I’d forget about it!” “What?” asked Tom hopefully. “Why, I gave you the wrong thing! There wasn’t any ten-dollar bill in that envelope!” “There wasn’t?” and Tom’s heart grew light again. [Illustration: “Why, I gave you the wrong thing!” said Dr. Spidderkins. _Page 50._] “No. That envelope contained a list of books I wanted Mr. Townsend to get for me. I meant to send it back to him by whoever called for the ten dollars. I put the envelope in the compartment with the bill, so I would remember about it. Then my memory played me a trick, and I gave you the envelope with the list, and not the bill. So you haven’t lost much of anything, after all. I can easily make out another list, and here is the ten-dollar bill. Queer how that happened.” “I guess it’s a good thing you didn’t give me the money,” said Tom with a smile, “for I would have lost it. But I’ll be careful this time.”