Sky Island: being the further exciting adventures of Trot and Cap'n Bill after their visit to the sea fairies

Trot meets Button Bright who has a magical umbrella which takes him where he wants to go. Trot, Button Bright and Cap'n Bill decide to use the umbrella to take them for a picnic out on an island just off the coast. Instead of being taken to that island, however, they wind up on and island in the sky inhabited by tow warring peoples. Our characters wind up in the middle and have to set everyone straight.