The Landon family travels to Everglades National Park to investigate a strange illness among the already endangered manatees. Deadly Waters finds Jack, Ashley, and their family's new foster child, Bridger, face-to-face with sharks, alligators, and a stranger intent on stealing Jack's camera.

This exciting mystery-adventure story introduces readers to the ecology of Everglades National Park, with a special focus on Florida's threatened manatees.