Fu Dog takes Jake to his first Boulder Ball game but seventeen periods of games prevents Jake from getting real sleep. At school, Hans Rotwood informs his class that there would be a test on Friday that would count over fifty percent of their grades. Jake then learns he has another mission as the American Dragon--to protect the Oracle twins from Herbert the Goblin who planned to capture them and use them to make predictions on the upcoming Ogre Bowl. Since the Oracle twins can't predict when Herbert is coming after them, Jake has to protect them for the whole week.
Jake later introduces the twins, who are posing as his cousins from out of town, to Trixie and Spud. When they find out that the twins are seers, Trixie tries to get them to make a prediction of her. Kara tells her that she and Spud will "tie the knot", which freaks out Trixie. Meanwhile two goblins have poorly disguised themselves as teenage girls to get near the twins. Jake has trouble silencing the Oracle twins from making predictions to his school, which Kara tells Jake is physically impossible for them to do. The Oracle twins cannot lie about their visions which is certain to happen a hundred percent true. To prove that their visions don't come true all the time, Spud leaves the school and goes to the school's front to clear himself of any chocolate milk. But Spud trips and his yo-yo falls from his hand just as a truck carrying chocolate milk comes. Trying to stop the truck from running Spud over, the truck tips and spills the chocolate milk just as the Sara predicted.
When Jake and the Oracle twins are walking home, they take a shortcut through an alley. Sara falls and loses her sandal, which Jake goes to retrieve, and laughs about it. Jake is still confused about why someone who only sees bad stuff is so happy while someone who only sees good things is miserable. the two explain thay Kara's good visions has made life dull for her while Sara's bad visions makes her appreciate every bit of good news. Sara then has a prediction that goblins would fall from the sky. Herbert's goblins surround them, and Sara's prediction that the alley would be filled with rotten fish helps Jake fight them off since the fish's odor irritates the goblins' high sense of smell.
Jake flies the Oracle twins to the rooftop for safety. After Kara has a prediction that Jake would get an answer right on his mythology test, Jake tries to use them to have more predictions on his test's answers. At lunch, Sara has a prediction that someone would take the last pudding from Rose so Jake steals it for her. Jake tries to use them to help him with Rose as well. After saving Rose from tripping downstairs, Jake is sent to his mythology class by Professor Rotwood without escorting the Oracle twins to the office.
During his test, Jake receives a message from the fairy messenger that the Oracle twins were going to be kidnapped by the goblins. Jake leaves the class despite Rotwood failing him and finds Sara's sandals in the hallway. With Grandpa and Fu Dog, they head to the Ogre Bowl to find the twins. Sara's earlier predictions of smelling pixie schnitzel helps Jake locate them faster. Herbert takes the Oracle twins and runs across the field. Despite Sara's earlier prediction that Jake would be hit by a boulder going 180 miles per hour, Jake flies to them and distracts Herbert, having him collide with the ogres so that he lets go of the twins. Jake catches the twins but seeing the boulder near him, he throws Sara and Kara against a float. Since he was flying at the speed of 179 miles per hour, his tail tapped the boulder away without getting injured. Unfortunately, he crashes against the stands. Kara and Sara thank him for saving them.
As Trixie and Spud walk home, Spud needs help tying his shoes. Trixie helps him by tying his shoes in a knot, and they realize that was what the Oracle twins meant. Jake walks the twins back to Magus Bazaar to their home, where Sara warns Jake about Rose's dark secret before closing the door on him.
- When Jake go into the hallways to check on Sara and Tara, he see one of Sara's filp fops, but at the ogre bowl Sara is seen having both flip flops on her.