Bored at his own birthday, Jack is tired of toys that do everything for him. But then he opens the Think-a-ma-Jink. The instructions read: “Relax, open your mind, and repeat the words: / Think / Think / Think-a-ma-Jink / Hulla-ba-loo / Razza-ma-doo.” Suddenly Jack and his sister Marie can be and do anything they imagine. Jack becomes a monster attacking a city, and the siblings travel by hot-air balloon through space and time. But when Jack and Marie get involved in a battle to turn each other into various imaginary creatures, the Think-a-ma-Jink breaks. Will the adventures come to an end? Whamond’s brightly colored watercolor artwork reflects an active imagination. Wonderfully expressive faces and busy illustrations will keep readers searching the scenes for more details. Although the pictures in one instance do show the toys that Jack uses to engage his creativity, readers whose imaginations are a little rusty may need more direction as to how to go about using props to fuel their journeys—this would be well-paired with Wilfried Gebhard’s What Eddie Can Do (2004). (Picture book. 4-7)