In an instant of time the girls had added their strength to his and the automobile was moving slowly down the road. Luckily the car was on a down grade or they never could have managed it. As it was, there was just time to get out of the way when the great tree came crashing down, its outermost branches just brushing Amy's skirt. The giant had fallen on the very spot where the car had been only a moment before! "Girls," breathed Betty, with a shaky little attempt at a laugh, "I guess we've never in our lives been nearer death than we were just then." And while the girls are marveling at their almost miraculous escape from a terrible death, time will be taken to introduce the Outdoor Girls to those readers who have not yet met them and also to review briefly a few of the exciting and interesting adventures they have had up to the time of this present narrative. There were four of them. Betty Nelson, or the "Little Captain" as the girls often called her because she had such a decided talent for knowing just the right thing to do at just the right moment, was eighteen, dark-haired and dark-eyed. She had a fund of vitality and more than her share of sense and good judgment--all of which went toward making her what she was, the most popular girl in Deepdale. Grace Ford, tall, slender and willowy, was almost the same age as Betty, but that fact and her love of the outdoors were the only things she had in common with the "Little Captain." Her father, James Ford, was a lawyer, and her mother, Mrs. Margaret Ford, a rather dressy lady who spent a good deal of her time at clubs, was quite a figure in the society of Deepdale. However, all through the war Mrs. Ford had worked with an untiring enthusiasm for the "cause," a fact which had made her many more friends than her social popularity could ever have done. Next in the little quartette came Mollie Billette. Mollie was seventeen, French-American, and impulsive, with a quick temper that made more trouble for herself than for any one else. She and Betty were alike in their splendid vigor and vitality. Mollie, or "Billy" as she was sometimes called by her chums, had a very lovely widowed mother and an extremely mischievous young brother and sister, Paul and Dora (nicknamed "Dodo"), who were twins and six. Although the twins were pretty nearly always in trouble, they were really adorable children, whom everybody loved. Amy Blackford, shy, sweet, pretty, completed the quartette. There had been a mystery about her past which had recently been cleared up, and it may have been this mystery that caused the girls to treat her with a little more consideration and gentleness than they did each other. Her guardian was a broker in the city who knew very little of the past except through letters.