Such were the words that Dave murmured to himself as he dashed away from Phil’s side, making off in the direction where he had last seen Roger Morr. As he advanced he adjusted his gas mask, knowing that it would be foolhardy to move along without it, even though it somewhat impeded his breathing.

Dave was filled with a great fear for the welfare of the lad who had been his chum for so many years and who just before leaving home had become engaged to his sister.

“If he’s all right, he’ll know how to make use of his gas mask, even if the mouthpiece is broken,” he reasoned to himself. “But if he’s badly wounded, or is unconscious, he won’t be able to save himself when the gas reaches him. Oh, I’ve got to find him—I’ve just got to!”

To those of my readers who have perused one or more of the former volumes in this series, Dave Porter will need no introduction. For the benefit, however, of those who are now meeting Dave for the first time, let me state a few facts concerning his boyhood and the years immediately following.

When a very small lad Dave had been found wandering alongside the railroad tracks in Crumville in one of our eastern States. No one came forward to claim him, and he was put in the local poorhouse and later on bound out to a one-time college professor, Caspar Potts, who was then farming for his health.

In a fine mansion on the outskirts of Crumville dwelt Mr. Oliver Wadsworth, a wealthy jewelry manufacturer, with his wife and his daughter Jessie. One day the gasoline tank of an automobile took fire, and little Jessie was in danger of being burned to death when Dave, who chanced to be near, rushed to her rescue. Because of this brave act, the rich jewelry manufacturer became interested in the boy and decided that he should be given the benefit of a good education.

The lad was sent to a first-class boarding-school, as related in the first volume of this series, entitled, “Dave Porter at Oak Hall.” With Dave went Ben Basswood, his one friend in the town.

At Oak Hall, Dave made a host of friends, including Roger Morr, the son of a well-known United States senator; Phil Lawrence, whose father was a rich shipowner; Maurice Hamilton, who loved to tell stories and who was generally known as “Shadow” because of his thinness: and Buster Beggs, who was as stout as he was good-natured.

It can be easily understood that in those days the principal thing that troubled Dave was the question of his parentage. Some mean schoolboys called him a “poorhouse nobody”; and to solve the mystery of his identity he took a long voyage, as related in “Dave Porter in the South Seas.” He met his uncle, Dunston Porter, and learned much concerning his father, David Breslow Porter, and also his sister Laura, who were at that time traveling in Europe.

After his trip to the South Seas, Dave returned for a while to school, but then went to the Far North and succeeded in locating his father.