Marbleholders is a fiction business and mystery novel about Kidswork Corporation, founded in 1944 by a ten-year old child named Dinky. All of its equity owners, investors, and employees are required to be children. Marbles are used instead of stock certificates, and baseball cards are used instead of bonds. Kidswork Corporation has all the experiences of today's large public corporations albeit on a miniature scale. The surprise ending comes when Dr. Dinky is ninety-one years old.