Behind the Green Door, Mildred A. Wirt, 1958 Juvenile Mystery

Behind the Green Door by Mildred A. Wirt (best known as the original ghostwriter of many Nancy Drew titles) is a classic juvenile mystery originally published in 1940, with this Cupples & Leon edition copyrighted 1958.

The story follows young reporter Penny Parker as she becomes entangled in a suspenseful investigation involving coded messages, strange noises, hidden cabins, and the mysterious green door at the center of it all.

This hardcover copy shows light spotting and general wear to the blue cloth boards, consistent with age, but the interior pages remain clean with crisp black-and-white illustrations.

A solid vintage copy for collectors of early girl-detective fiction or fans of Wirt’s work outside the Nancy Drew series.