Josie gets sucked into a vortex, sending her three hours into the past. If she doesn't enter the vortex when it is time, she will be stuck in an alternate dimension. Meanwhile, Josie's mother thinks about cooperating with Victor.
When Madison runs for President of the Student Council, Josie runs against her for the sole purpose of defeating her. Josie promises to change the system of grading, while Madison uses pheromones to capture everyone under her control.
Marshall is going about the school with a cold, and his sickness spread via wireless computer networking to the entire school with chills, fever, and sneezing. People who have purchased a special computer system that allows them to surf the web are demanding refunds when thick mucous is disrupting the system.
A class DNA project goes awry when Lucas' DNA is altered and his personality changes from shy and nervous to absolutely fearless, but lacking self-control. His friends must save him from Stu Kubiak, who calls a fight with him.
Vaughn is helping Lucas with an E.E.G. experiment. A circuit board blows, resulting in Lucas' personality moving into Vaughn's body and Vaughn's moving into Lucas' body. They learn about what its like to be each other and the Science Club has to straighten out the mess. Also Josie and Lucas do a scene from Romeo and Juliet.
Marshall's older brother Grant comes to town when applying for a job at Pearadyne, but an accident with molecular models sends Marshall through the periodic table, into helium, oxygen, neon, chlorine, and on the path to uranium. Meanwhile Grant becomes sodium as he arrives at school. The two eventually meet, and are turned back to normal by forgiving each other, producing the stable molecule sodium chloride (table salt).
A misunderstood statement turns into gossip about Josie as she sneaks around in preparation for a birthday surprise. Also, Corrine accuses Josie of being a kleptomaniac and the school rapidly fills with sponges. Professor Z., Marshal, and Lucus try to get rid of them with boy-band music.
The Academic Olympics team trains under Capt. Corrine (who is obsessed with winning). Josie, Lucas, Marshall, and Vaughn must figure out why they are doing things they normally couldn't or shouldn't be doing.
When Corrine auditions for Magnet 360 (Marshall's band) as a singer, she looks at an antique mirror, through which she travels. Everyone there is opposite (for example, Vaughn, the athlete, is a bookworm) and everything appears as a mirror image (i.e. whenever she would normally, say, go left, now she must go right). To return, Corrine must learn to use the creative half of her brain without losing her ability to use her logical side.
Students are becoming addicted to energy bars, especially Lucas and Vaughn, who aren't willing to give them up. The others must attempt to save them when it is discovered they contain zero calories or energy, thus weakening the addicts.
Josie and Vaughn go on their first date. Josie's watch allows her to stop time which is good at first until she can't control it and only Lucus can save her. Also Josie finds out who took her missing Qui-chong ball and the return of an old friend.