It is a historical novel. On a time it happened that the light-house keeper in Aspinwall, not far from Panama, disappeared without a trace. Since he disappeared during a storm, it was supposed that the ill-fated man went to the very edge of the small, rocky island on which the light-house stood, and was swept out by a wave. This supposition seemed the more likely as his boat was not found next day in its rocky niche. The place of light-house keeper had become vacant. It was necessary to fill this place at the earliest moment possible, since the light-house had no small significance for the local movement as well as for vessels going from New York to Panama. Mosquito Bay abounds in sandbars and banks. Among these navigation, even in the daytime, is difficult; but at night, especially with the fogs which are so frequent on those waters warmed by the sun of the tropics, it is nearly impossible. The only guide at that time for the numerous vessels is the light-house. The task of finding a new keeper fell to the United States consul living in Panama, and this task was no small one: first, because it was absolutely necessary to find the man within twelve hours; second, the man must be unusually conscientious, —it was not possible, of course, to take the first comer at random; finally, there was an utter lack of candidates. Life on a tower is uncommonly difficult, and by no means enticing to people of the South, who love idleness and the freedom of a vagrant life. That light-house keeper is almost a prisoner. He cannot leave his rocky island except on Sundays.