The Thornberrys are in the Florida Everglades to film the Endangered Snail Kite. It is also Nigel's birthday and Marianne and the girls have a brand new watch/compass for him. While Marianne and Nigel go off to film the girls and Darwin and Donnie explore the Everglades in an air boat. Debbie wants to keep track of their time and brings the new watch. Soon they get lost and while using the compass drop it overboard. A Swamp Witch and a hungry alligator will make getting it back very difficult.