This is the seventh book of this twelve part series, written by Maj. Archibald Lee Fletcher.
Boy Scouts on Old Superior marks a major change in the tone and flavor of the series. Starting with this book, Fletcher leaves behind the familiar characters and exploits of the boys of the Beverly, Indiana, Beaver Patrol, and turns to their compatriots in the Beaver Patrol of Chicago. This new group of boys, like their small-town brethren live shortly after the turn of the twentieth century, are more street-wise due to having lived in an urban environment all their lives. Like the characters in the previous stories, they drew together to start a Boy Scout troop of their own, and decided to take the hardworking Beaver as their symbol. Unlike the more rural boys we have read about earlier, however, they find themselves in a city in which the Boy Scouts already have a significant presence, and do not encounter mistrust and ignorance of the Scout mission. Their challenges have more to do with the toughs that inhabit the places they visit than with rival patrols.
In this seventh volume, the Beavers become involved with Chicago police and, as way to avoid one of their members going to jail, end up on the trail of smugglers who inhabit a mysterious series of caverns along the shores of Lake Superior.