故事發生在Mulch 島。Ned從小失去一條腿,得坐在輪椅行動。Ned的姊姊,因為弟弟總是得到注意而討厭弟弟。這個島的大人也幾乎都很不友善。學校有最懶老是打瞌睡又愛吼叫的老師;公園的管理員不准小孩進入公園;冰淇淋車老闆夫婦會偷小孩錢,不給他們冰淇淋。最最最不友善的竟是媽媽的姊姊,她也是島主,一個人和101隻貓住在中世紀城堡,俯瞰小鎮。她討厭小孩,認為小孩是破壞的根源。這恐怖的島,需要改變。誰有勇氣,能推翻、登高一呼呢?來看看Ned,這位輪椅男孩,和他的史萊姆,如何改變死氣沉沉的Mulch 島。書末有史萊姆小外傳,討論他從何而來,有什麼超能力等。
The new children's book from No. 1 bestselling author David Walliams - a fantastically funny tale illustrated by artistic genius, Tony Ross. WELCOME TO THE ISLE OF MULCH... This little island is home to a large number of horrible grown-ups. The school, the local park, the toy shop and even the island's ice-cream van are all run by awful adults who like nothing more than making children miserable. And the island is owned by the most awful one of all - Aunt Greta Greed! Something needs to be done about them. But who could be brave enough? Meet Ned - an extraordinary boy with a special power. SLIMEPOWER!