Molly Moon, Micky Minus and the Mind Machine by Georgia Byng
Molly Moon is on a mission - to bring her long-lost twin brother, Micky, home. But before she can rescue him she has to find him, and he could be anywhere! Luckily Molly's time-travel talents and world-stopping skills help her in her search . . . until a baby-faced villain with a precocious plan to have the world's biggest brain gets in her way. Can Molly, Petula the dog and their best friend, Rocky, use Molly's new secret weapon - mind reading - to defeat the brainy babe and her monstrous mind machine?