Trang, Bindu, and Squeaker expect the return of their parents from a mysterious trip abroad. Trang, the eldest, has been in charge of the family while the parents are away. But when the parents don't return on the expected date the kids decide to try and find out where they might have gone, and begin a search in their inventor father's secret workshop for clues. The kids find their father's and mother's journals and a treasure map. Then they must solve the puzzles in the journals to find the paths that will lead them to the treasure and their parents. However, an associate of their father's, Dr. Kropulent, wants to steal the journals and find the treasure for himself. But the kids evade him by escaping in their father's time machine - setting off on a journey to different countries and through different ages - following clues that will lead them to their parents and the treasure.