Drew is ten, he loves to draw, and his parents are divorcing. One day, while running from some bullies, he crawls into a cave, and finds himself in a parallel world. He meets Miss Jane and her butler Stewart; both of whom seem very nice. Jane teaches him to water walk, and says he can stay. In gratitude, Drew offers to journey to the land of the dragons and speak to them on her behalf. She wishes to expand her magical realm, and needs their permission to do so.
Water walking into the next realm, Drew is sucked into a submarine, where he meets Captain Paul and his white mice – Peter and Mary. When the sub is attacked by a giant squid, Drew tries to help, but accidentally gets shot out a torpedo tube! He’s rescued by some mermaids who try to help Captain Paul, and lead Drew to the Cliffs of Celeste.
Latching onto a Travel Vine, Drew is pulled into the village of some Ticals – people who live vertically on the face of the cliff. They throw Drew in prison for being a zontal – someone who lives horizontally. Later, the village is attacked by someone (Drew figures it’s the dragons) higher up the cliff. Going before the Tical council, Drew convinces them to let him travel up the cliff to try and talk to the dragons and end their war.
By using another Travel Vine, Drew reaches the land of the dragons. They didn’t know the Ticals were living on the cliff; they’ve been throwing their trash over the edge. Ironically, this has led to a shortage of seeds they need to grow the trees they live in. The dragons get the seeds from the mermaids, but they’ve been helping Captain Paul fight the squid. He’s needed their help because he can’t get Lightning Juice from the Ticals; they’re using it to destroy the boulders the dragons have been throwing over the cliff.
Drew is able to solve all of their problems, and the dragons are grateful. When he asks if Jane can cross their realm, they refuse. They’re suspicious of her, and advise him to go home. The dragons tell him to find the Great Map, and ask it for the truth. Before leaving, the king gives Drew a dragon flute – so that he can call to them anytime he wants. One of them flies him home, and he sneaks into Miss Jane’s lab. There he finds the map and draws a picture of Jane on it, and the little figure becomes animated. Drew sees that she plans to destroy all the realms, and decides to leave.
Unfortunately, Jane and Stew capture Drew, and throw him in the high tower until he agrees to summon the dragons. He manages to escape out onto the roof and slips into the main house. There he runs into Stew, and he tells Drew that he’ll help him to escape. Jane has never been very nice to Stew – ever since she made him out of clay – whereas Drew has, and Stew wants to repay Drew’s kindness.
Down in the great hall, Drew realizes that the clay statues there are real children trapped in clay! He shatters them, freeing the children, and together they race for the cave. Jane, now changed back to her true form (a giant snake), chases them. Drew leads her away from the others, and together with Stew they delay her long enough for everyone to escape. Finally, Drew enters the cave and Stew blocks the entrance.
Emerging from the cave, Drew leads the children home. His parents, worried over him, have patched things up. While startled at the sight of so many orphans, they elect to take them in. In the end, Drew is left with only his dragon flute and the map, and wonders if he’ll ever go back to the magical realms.