The book is an adventure story about two brothers, Matt and Sam Burns, who discover the minutesof the Viking Club, a secret society of boys from a generation or so earlier, in their grandmother's cellar.
A section in the back gives full instructions on making regalia for club members, including masks, shields and (dull-pointed) spears.
[1] These could be easily made by the book's target audience, with mostly household materials;[1] a bushel-basket lid is the hardest item to obtain.
A sequel to the book, Enemies of the Secret Hide-Out, appeared in 1966, and was also a longtime title for Scholastic.
In this story, two boys try out for membership; when one is disqualified for cheating, he starts a rival club, and threatens to learn and expose the location of the hide-out.