Nelson Kramer can't wait for the annual Sports Day. As a ninja, he should be able to win a few gold medals. But when something goes wrong with his grandmother's new invention, his powers and hers are switched. While his grandmother suddenly does rapid backflips, Nelson is in pain all over and longs for a cup of tea for the first time in his life. This spells disaster not only for all the competitions, but also for the Sports Day winners, who are kidnapped. How will Nelson save them without his ninja powers? The Worst Ninja Ever is the third installment in the hilarious Ninja Kid series by popular Australian children's author and comedian Anh Do.