The Case of the Double CrossBook - 1980
It takes perseverance, ingenuity, and the baffling appearance of little bearded men writing messages in code before Marigold and her friends can prove their worthiness to join the boys' exclusive Private Eyes Club
Wizard's private eyes don't want any girls, and the sign on the clubhouse door says just that:
But Marigold and her friends dream of joining the club. And when a funny little man double-crosses the private eyes with a message in code, the girls get to show just how clever they really are.
Would-be detective or not, every reader will chuckle over the pictures of these comical kids and how the wizziest bunch of private eyes around finally get together.Children's Books of 1980 (Library of Congress)
Children's Books of the Year 1983 (CSA)
Marigold concocts a mystery that finally gets her and her friends into the boys' private eye club.