Signal in the Dark

by Mildred A. Wirt

  CHAPTER 11 _A FAMILIAR CAR_

  Louise gazed again at the automobile parked in the lane and at itsmud-splattered license number.

  "D F 3005," she read aloud. "What about it, Penny?"

  "Why, that is the number of the car that went off with Salt Sommers'camera and plates the night of the big explosion," her chum explainedexcitedly.

  "You're sure it's the same auto?"

  "It certainly looks like it. Now I remember! Salt traced the license toan owner named Bettenridge!"

  Hopeful of recovering the lost property, Penny, with Louise close at herside, tramped through the high grass to the deserted lane. Apparently thecar owner had not gone far, for the doors had not been locked.

  Penny climbed boldly in. A glance assured her that the camera or plateswere not on the back seat where they had been tossed. As Penny ran herhands beneath the cushions, Louise plucked nervously at her skirt.

  "Someone is coming, Penny! A man and a woman! They're heading straighttoward this car."

  "All the better," declared Penny, undisturbed. "If they own the car, wemay be able to learn what became of Salt's property."

  The man, middle-aged, was tall and thin and wore rimless glasses. Hewalked with a very slight limp. His wife, a striking brunette, whoappeared many years his junior, might have been attractive had she notresorted to exaggerated make-up.

  "Good afternoon," the professor said, eyeing the girls sharply. "My carseems to interest you."

  "I was searching for something I thought might be on the back seat,"Penny explained.

  "Indeed? I'm afraid I don't understand."

  "I was looking for a camera and plates."

  "I regret I still fail to follow you," the man said stiffly. "Why shouldour car contain a camera? My wife and I take no interest in photography."

  "Aren't you Professor Bettenridge?"

  "I am."

  Penny gazed again at the car. "This must be the automobile," she said,deeply troubled. "On the night of the Conway Steel Plant explosion, Itossed a camera and photographic plates into the back seat to preventthem being destroyed by a mob."

  "Not this car," said the professor with quiet finality. "I have not beenin Riverview for nearly a month."

  "A woman who resembled your wife was driving the car."

  "Are you accusing me of stealing a camera?" the woman demanded angrily.

  "Oh, no! Certainly not! I just thought--" Penny became confused andfinished: "The camera was expensive and didn't belong to me."

  "I know nothing about the matter! You certainly have your nerve accusingme!"

  "Come, come," said the professor, giving his wife a significant, warningglance. "There is no need for disagreement. The young ladies are quitewelcome to search the car."

  "We've already looked," Penny admitted. "The camera isn't there."

  "Isn't it possible you were mistaken in the automobile?"

  "I may have jotted down a wrong license number," Penny acknowledgedreluctantly. "I'm sorry."

  She turned to leave.

  "That's quite all right," the professor assured her, his tone nowbecoming more friendly. "Do you girls live near here?"

  "In Riverview," Louise supplied eagerly. "We drove over for a picnic.Mrs. Leonard told us about your light ray machine!"

  "Indeed." Professor Bettenridge looked none too pleased.

  "She said you might be willing to show it to us."

  "Mrs. Leonard displays a remarkable interest in our affairs," Mrs.Bettenridge commented sarcastically.

  Again her husband shot her a warning glance.

  "My dear, it is only natural that she should be interested in such anamazing machine as ours," he said. "I see no reason why the young ladiesshould not view it."

  "Oh, may we?" Louise cried eagerly.

  Although his wife scowled with displeasure, the professor bade the girlsfollow him to the nearby shack. The door was padlocked and he opened itwith a key.

  Inside, the room was bare of furniture. There were a few boxes and alarge table upon which rested a sizeable object covered with canvas.

  "My secret ray machine is expected to revolutionize warfare," theprofessor said proudly. "Behold the product of fifteen years of faithfulwork!"

  Dramatically he jerked aside the canvas cover, revealing a complicatedmechanism of convex and concave mirrors which rotated on their bases. Inthe center of the machine was a small crystal ball.

  "How does it operate?" Louise asked, deeply impressed.

  "I am afraid a technical explanation would be too involved for you tounderstand. Briefly, a musical note produced on the crystal globe, iscarried by ultra violet ray to the scene of the mine. The vibration willcause any unstable substance such as melinite to explode."

  "And you claim you actually can explode mines with this machine?" Pennyasked.

  "I not only claim it, I have demonstrated the machine's powers,"Professor Bettenridge replied. "How I do it, of course, is my ownsecret."

  "Will you explode a mine for us now?" Louise questioned eagerly.

  Professor Bettenridge looked mildly amused. "My dear young lady," hesaid. "Do you realize that mines are very expensive? I have been able toobtain only a few, and naturally I must save them for official tests."

  "Of course," stammered Louise. "I hadn't thought of that."

  "Besides, the demonstrations have a certain element of danger," theprofessor resumed. "I never give one without my assistant."

  Penny, who had been studying the machine with increasing interest,remarked that a story about it might make an interesting feature for the_Star_. To her surprise, the professor did not seem to favor the idea.

  "You are employed by a newspaper?" he inquired.

  "Yes, the _Star_."

  "I must ask you to say nothing about this matter," the professordirected. "Under no circumstance could I permit a story to be writtenabout my work."

  "But why?"

  "Publicity at this time might rob me of an opportunity to sell themachine. A very prominent man, James Johnson, is now considering itspurchase."

  "But I thought you were expecting to sell your invention to thegovernment," Penny said, puzzled.

  Professor Bettenridge bit his lip. Obviously, he was beginning to sharehis wife's annoyance at the girls.

  "I regret I can't tell you all the details of my negotiations," he said."My wife and I are very tired, so if you will excuse us--"

  "Certainly," said Penny, taking the hint. "Louise and I must be on ourway to Riverview."

  They started to leave, but before they could reach the door, someonetapped lightly on it. Professor Bettenridge and his wife exchanged aquick glance which Penny could not fathom. For a fleeting instant, shethought they both looked frightened.

  Then the professor went to the door and opened it. A little man in aderby hat and with an apologetic manner stood on the threshold.

  "Mr. Johnson!" exclaimed the professor, extending his hand. "My wife andI did not expect you until tomorrow."

  "I came a little sooner than I planned," the newcomer admitted. "Abusiness conference I had expected to attend was postponed untiltomorrow. Naturally, that has upset my schedule. I had hoped you mightconsent to a demonstration of your machine tonight."

  "Tonight?" The professor seemed caught off guard. "But that isimpossible!"

  "Impossible?" inquired Mr. Johnson. "Why?"

  "For one thing, my assistant is not here."

  "Can't you get in touch with him?"

  "I doubt it. Besides, I have another engagement." The professor hesitatedand added: "Officials of the Navy have invited me to confer with themtonight at the Gables Hotel in Riverview. I rather expect them to make mea very attractive offer for my invention."

  "But you promised me first option on it!" Mr. Johnson protested. "Ifnecessary, I can wait for the demonstration tomorrow night, though itwill greatly inconvenience me."

  "Tomorrow at eight o'c
lock," the professor nodded. "If you should care toput up a small sum of money as a guarantee of your intentions, I promiseto make no final deal with the Navy until after that time."

  "Why, yes," Mr. Johnson agreed, taking out his check book. "Any amountyou say."

  Feeling themselves no longer welcome by the Bettenridges, Penny andLouise slipped quietly away. As they climbed the hill they could hear theprofessor and Mr. Johnson discussing the amount to be paid.

  "It's a graft, if you ask me," Penny declared. "Poor Mr. Johnson seemshypnotized."

  "I wish we could see that test tomorrow night!"

  "So do I. In fact, I'd be willing to bet the machine won't work."

  "What makes you think so?"

  "Just my doubting nature, I suppose. No, there's more to it than that,Lou. Didn't you notice how startled the Bettenridges were when their starcustomer appeared?"

  "They did look a bit upset."

  "And the professor refused to give a demonstration tonight, althoughobviously it would have been to his advantage."

  "He explained he had an engagement with Navy men."

  "Which I suspect was all a made-up story. No, Lou, there must be anotherreason why the professor was unwilling to give the demonstration. Heprobably knows his machine won't work."

  "You're convinced he's a fraud."

  "Yes, I am," Penny said. "Furthermore, I believe he knows what became ofSalt's camera."

  "We can't prove anything."

  "No, but if he would steal a camera he might also take to swindle in abig way."

  "There's nothing we can do unless we want to report him to the police."

  "I have a little idea," Penny confessed. "As soon as we reach Riverview Ipropose to check the Gables Hotel and learn if any Navy men haveregistered there. By talking to them, we may get at the truth."