Fardell, John

Fed up with just drifting round the ocean with his shoal, Jeremiah Jellyfish trades places with the stressed-out director of the biggest rocket plane company in the world.

Eleven-year-old Sam finds himself involved in a dangerous adventure when he and his new friends, brother and sister Ben and Zara, set off for the Arctic to try and rescue the siblings' great-uncle and five other professors from the mad scientist holding them prisoner.

Ben, Zara, Sam, and Marcia begin their summer vacation by helping Professor Ampersand and a new friend build the Silver Turtle, a futuristic airplane, but on the day the first test flight is planned, a strange woman steals the airplane with the children inside.

When Sarah's brother, Louis, is eaten by a Gulper, Sarah does not panic but follows the trail as the Gulper is eaten by a series of other creatures until finally she has her chance to rescue Louis from them all.

Eleven-year-old Sam finds himself involved in a dangerous adventure when he and his new friends, brother and sister Ben and Zara, set off for the Arctic to try and rescue the siblings' great-uncle and five other professors from the mad scientist holding them prisoner.