La vie de Milo est bouleversée lorsqu'il trouve un beau jour un mystérieux paquet contenant... un poste de péage en kit et la carte d'un pays inconnu. C'est le début d'un voyage merveilleux dans les cités fantasques de Dictionopolis et Digitopolis ; la première prônant la suprématie des mots, l'autre celle des chiffres...

For Milo, everything’s a bore. When a tollbooth mysteriously appears in his room, he drives through only because he’s got nothing better to do. But on the other side, things seem different. Milo visits the Island of Conclusions (you get there by jumping), learns about time from a ticking watchdog named Tock, and even embarks on a quest to rescue Rhyme and Reason! Somewhere along the way, Milo realizes something astonishing. Life is far from dull. In fact, it’s exciting beyond his wildest dreams...