The Panther Mystery — Gertrude Chandler Warner

One warm night four children stood in front of a bakery. No one knew them. No one knew where they had come from.

Henry, Jessie, Violet, and Benny used to live alone in a boxcar. Now they have a home with their grandfather, and they are going to visit Florida.

The Aldens travel to Everglades National Park to help find one of Grandfather's friends. Andrew Beldon, a park ranger, has been missing for several days. Yet, everyone the Aldens question seems angry and secretive instead of worried. Henry, Jessie, Violet, and Benny are determined to solve this mystery, even if it means following Andrew's trail deep into the spooky Everglades.