Books like The Hollow Chest by Phoebe Atwood Taylor

Witherall, a police officer, returns home after escorting the Fifth Form on their annual outing. While the point is to have a field trip that involves a rousing game of Fox and Hounds, every good fifth former knows to conceal eggs about his person because somebody, somewhere along the way is going to need a good egging. When a General who is directing practice maneuvers comes into their sights--in a tank, no less--they know they have found their target. Witherall has to lead the boys in a strategic retreat and finally winds up back at the school with all the boys intact. Or so he thinks. He later learns that at some point they picked up a stray boy and lost the fox, Sandy Threewit--who just happens to be the ward of a very rich, very prominent lady who just might have money to donate to the Academy. After returning home from these adventures, Witherall finds his home ransacked and a beautiful girl (who he doesn't know) bound, blindfolded, and gagged on his bed upstairs. He starts to untie her bonds when the police arrive. He manages to convince them that nothing strange is going on (he doesn't want to much attention from the police lest they discover that he's the man who was shepherding the boys who egged the general) and when he goes back upstairs he finds that the girl has disappeared. Next up is a phone call from Mrs. Vandercook (guardian to the lost Threewit), she's not calling to inquire about the boy (thankfully), but she wants Witherall to dress up in formal wear, go the corner of Eighth and Oak Streets, collect George and go to the Corner of Elm and Oak.

First publish date: 1941