By this time they had reached the road and Mollie went straight to the car. While she and Betty were trying to find out what was wrong the other two girls and Professor Dempsey looked on anxiously. "Well, as far as I can see there is absolutely nothing wrong with it," snapped Mollie at last, lifting a face flushed with exertion. "Get in, girls, and I'll start the engine--or try to. Then if she won't go we'll have to make up our minds to stay here all night or walk to the next garage." Accordingly the girls got in and Mollie pressed the self-starter. To her great surprise, the engine purred a response, and as she shifted her gears the car moved slowly forward. "Oh, goodie, we're going," cried Amy, and the faces of the other girls showed relief. "Must have been a drop of water in the gasoline," hazarded Mollie, and then she throttled the engine once more while she and her chums turned to say good-bye to Professor Dempsey. The latter was still standing in the road, looking up at them rather wistfully. "I'm glad that I had an opportunity of helping you, young ladies--very glad," he answered, in response to their repeated thanks. "You conferred a great favor on me also, for I have little company. Good-bye--and good luck to you." The girls responded gayly, and as they started forward Betty leaned far out of the machine to call back an encouraging: "Keep hoping hard for your boys to come home. I am sure they will be back soon." "Thank you, young lady, thank you," said Professor Dempsey, but the words were too low for Betty to catch and she was too far away to see the mist that sprang suddenly to his eyes. Chapter IV Good News Deepdale, the home of the four Outdoor Girls, is a thriving little city with a population of about fifteen thousand people. It is situated on the Argono River, a pleasant stream where a great many of the young folk of Deepdale, and some of the older ones too, keep motor boats and canoes and various other types of pleasure craft. Farther on, the Argono empties into Rainbow Lake, which is picturesque in the extreme. It has several pretty and romantic looking islands, chief of which is Triangle Island--so called because of its shape. There is a boat running from Deepdale to Clammerport at the foot of Rainbow Lake, and this boat is almost always crowded with pleasure seekers. In addition to this Deepdale is situated in the heart of New York state and is only a hundred-and-fifty-mile run from the city of that name. Thus one can easily see that Deepdale is a very desirable place in which to live. At least that is what the four Outdoor Girls thought. And since they had spent most of their lives there, they certainly ought to know! On the morning of this day, some ten days or so after their strange encounter with Professor Dempsey, the girls were gathered on Betty's porch, talking over their plans for the summer.