The Gatehouse Mystery

determined to give you a driving lesson this afternoon, Jim. While Miss Trask was buying all the food in the village, he came back and polished the sedan. I'll say that for him."
    Trixie and Honey hurried into the house to change into swimsuits. "I wonder why Dick is so anxious to give Jim a driving lesson," Trixie said. "You'd think he'd try to get out of anything he could on a hot, muggy day like this."
    "I think he really means well," Honey said. "If only he were nicer to you, I'd like him."
    "Nothing would make me like him," Trixie said. "I wish I could see that letter from Mr. Whitney."
    "But why?" Honey asked.
    "Because," Trixie said, "I have a feeling the signature was forged. If you promise not to say anything to the boys, I'll explain. They'll just make fun of me."
    "I won't say a word," Honey said, curling up on the window seat beside Trixie. "I'm dying of curiosity."
    "It all depends," Trixie began, "on whether or not you went down for the mail at the regular time on Wednesday afternoon."
    Honey thought for a minute. "Wednesday. That was the day we found the diamond. Let's see— No, I forgot, as usual, Trixie, and the mail stayed in the box all night. I remember now. Miss Trask brought it up the next morning just when we were sitting down to breakfast. That's when Daddy found out he would have to leave for Chicago right away. If I'd remembered to bring up the mail Wednesday afternoon, he and Mother wouldn't have had to rush so with their packing."
    "I thought you probably forgot," Trixie said. "Now, don't you see, Honey? If someone was lurking around in the woods that day, he could have seen the mailman put the stuff in the box around five. Since it stayed there all night, he could have sneaked a letter out of the box that evening without anyone seeing him. A letter from Mr. Whitney."
    "I still don't understand," Honey said. "Why would anyone steal some of our mail?"
    "Signatures," Trixie said. "References have to have signatures. Anyone can rent a typewriter and type out the 'To whom it may concern' part, but to prove anything you have to have a signature."
    "Oh, oh," Honey gasped. "In the mailbox was a letter to Daddy from Mr. Whitney! Dick swiped it and copied the signature. Is that what you've been driving at?"
    "That's right," Trixie said.
    Honey frowned. "But Mr. Whitney doesn't sign his full name when he writes to Dad. He just signs himself "Whit.' I've seen it on Christmas cards. They're old, old friends."
    Trixie slid off the window seat to the floor, groaning. "I never thought of that. I just took it for granted that they did business together." Suddenly she brightened. "Don't they do any business together, Honey? I mean, mightn't there have been a contract or something like that which would mean that Mr. Whitney would have to sign his full name?"
    Honey thought for a minute. "I don't really know, Trixie. Anyway, do you think Dick would dare swipe a letter? Isn't robbing the mails a federal offense? Would he dare risk getting G-men on his trail just to get a job with us?"
    "The job," Trixie said, "isn't the point. He's after the diamond. I'm sure of it. If it's as valuable as you say it is, wouldn't he be willing to take a big risk to get it?"
    "I guess so," Honey said.
    "Anyway," Trixie went on, "Dick probably only borrowed the letter. Just long enough to steam open the envelope and copy the signature. He probably put the letter back in your box on Thursday while Bobby was showing him around the place. And in that case, there should have been a letter from Mr. Whitney in the Thursday mail."
    Honey sighed. "I wouldn't know. Jim collected the mail that day and gave Miss Trask all the letters that were for Mother and Daddy. Anyway, Trixie, just forging Mr. Whitney's nickname, 'Whit,' to the reference wouldn't have helped Dick any. Oh, now I remember." She suddenly interrupted herself. "Mr. Whitney and Daddy belong to the same club. Dad's the treasurer, and the dues are paid in August. There could very well have been a check from Mr. Whitney in Wednesday's mail."
    Trixie jumped to her feet. "Where does Miss Trask put your parents' mail, Honey? If we saw the envelope, we might be able to tell if the flap had been steamed open."
    Honey shook her head. "Miss Trask forwards all their letters right on to their hotel in Chicago. Let's go swimming, Trixie. It's so hot, and I don't see how you're going to prove that Dick is both a forger and a diamond thief."
    "If I had a piece of carbon paper and a piece