Dereck, is a normal thirteen-year-old boy who has agreed to take care of his five-year-old sister, Jessie, while their mother is away overnight. As the big brother, he intends to keep his sister safe, taking on the role of their dad who died in a car accident the year before. Derek loves his sister, but her constant need of his attention is starting to get on his nerves. However his mom is always reminding him to spend time with his little sister.
The only thing Jessie wants Dereck to do is read fairy tales to her, though he would prefer they do anything else like shoot bottle rockets or throw a baseball around. When Jessie takes a nap, a violent storm moves in, causing Dereck to stumble down the steps to the cellar of their home. When Jessie screams out for help, Dereck imagines a tree crashing through her window, trapping his sister in her room.
Trying to run to his sister’s rescue, he falls through the cellar floor and wakes up in Oz - an Oz filled with all the fairy-tale characters Jessie loves (and he hates) so much. Right away Dereck meets a farmer and his wife who live on the far side of a cornfield that grows beside the yellow road that weaves itself through Oz. The couple is waiting on the Dorothy girl from Kansas to pass by so they can make a deal with her. If she helps them catch a pesky man-sized crow, they will give her a secret map that shows a shortcut to the Emerald City.
But when Miss Glinda warns the farm girl not to take the shortcut, Dereck, with the help of the six-foot crow, decides to ‘borrow’ the map without the farmer’s knowledge so that Dereck can rush to the Wizard as quickly as possible so the great Oz might send him back to his sister who, he knew, was yelling for him to help her.
Dereck meets Miss Glinda’s personal assistant who has dressed herself like the good witch and calls herself Glindalina. Right before his eyes, the Wicked Witch of the West talks the assistant into becoming her evil assistant so she can help her make sure Dorothy will get the shortcut map, take the shortcut, and die so the green witch can get her hands on the silver slippers she wants from the farm girl so badly.
Miss Glinda is livid and scares the wicked witch away so that she won’t be able to give Dorothy the shortcut map. With the help of Crow, Dereck sneaks the map from Miss Glinda, and takes off down the yellow road where he battles a giant, a wolf, an ogre and somehow loses the yellow road, winding up in the middle of a thick forest where he runs into a little girl who wears a red cloak.
The girl introduces him to her grandmother who brings out an old photograph of a young man who favors Dereck a good deal. But how could that be? Within the short visit, the old lady finds out about Dereck planning to take the shortcut and gives him a safety charm since she heard that the shortcut between the yellow road and the Emerald City is a very dangerous path.
Dereck makes it to the shortcut path, finding a beautiful lady who quickly morphs into an ugly hag and tells Dereck he must die so that she and the other creatures kept captive there will be freed at last. Dereck remembers bottle rockets in his backpack and uses them to destroy the creature and catch the surrounding forest on fire.
Miss Glinda calls for a dragon to take Dereck home then and there. When Dereck arrives back to his house, he finds Jessie hiding in her bedroom closet as the storm outside has started to move away.
A few days later, Dereck notices in the artwork of Jessie’s fairy tale books, small things in the background like he had seen on his journey but were never mentioned in the age-old stories. He discovers the artist is from his own hometown and looks up the artist’s picture, realizing he looks very familiar and suddenly remembers the old photograph that Red’s grandma had shown him. That was the artist who had looked like him. But how could that be? Had the artist been to Oz too? Dereck has got to solve this mystery.