Luke and his brother have swapped bodies by accident. Zack`s got Luke`s weird feet while Luke has Zack`s SUPERPOWERS! Now he needs another world-threatening adventure to try them out. Could a family mini-break at Great Minds Leisure Park be his chance? Probably, because that`s where his super-clever arch-enemy lurks, fermenting dastardly plans and bubbling gently...`My Arch-Enemy Is a Brain In a Jar` is the fourth instalment of Luke`s laugh-out-loud adventures. From the author of `My Brother Is a Superhero`, winner of the Waterstones Children`s Book Prize and the British Book Industry Awards Children`s Book of the Year, and `My Gym Teacher Is an Alien Overlord`, winner of a Lollies Laugh Out Loud 2017 Book Award.