Elizabeth reveals a T-rex to a press conference at the school, but the T-rex rampages through the school. Toby creates a giant doll to fight the T-rex, and the doll wins. Toby zaps himself and Elizabth with the MFE, removing their genius. However, Elizabeth still has the genius key in the pocket.
Elizabeth takes Bianca captive in the hope Toby will give her the genius key, or she will use the shrink ray on Bianca.
Elizabeth clones Ms Vyner so she can control the school. Under threat of expulsion for being caught with the MFE, he tells Mr Tesslar everything about his genius. He goes to Ms Vyner about it, but he is really talking to Clone Vyner, and Mr Tesslar is fired.
Toby attempts to use the genius key to turn off Elizabeth's genius. Toby and Elizabeth meet secretly in the gym, and just as Toby prepares to cancel Elizabeth's genius, Mr Tesslar walks in seeing Toby with the stolen MFE.
Toby finds the correct sequence, called the genius key. He accidentally turns Russ into a genius.
Toby decides to create a visual memory for Russ who holds the missing element of how he and Elizabeth became geniuses.
Toby's nanna is sent back in time through a wormhole generator, and a younger version of Toby's nanna comes through the wormhole, destroying the generator.
Toby modifies the MFE machine to scan for Bianca in a rocky landscape. He finds a rock that reacts strangly with the MFE.
Toby creates a remote control that allows him to win an arcade game, but the game goes berserk.
Toby intercepts Elizabeth's teleportation machine, and Toby is teleported to Elizabeth's secret lab.
Toby makes special gloves which allow Russ to play the guitar like a rock star. Elizabeth launches her new line of makeup called Mood - which is a huge hit.
Elizabeth, in her basement lab uses too much power and Mr Tesslar tries to track it down, but she sets up Toby and Russ to keep the location of the basement lab safe.
Elizabeth sets up a secret lab in the school's basement, and orders Garth to shrink objects from the storeroom; but Dina discovers him. Panicking, he shrinks Dina.
Elizabeth is sacked as director of the school's centenary celebration, and vows to ruin the celebration by destabilizing the set.
Mr Tesslar installs a security camera to find out who is using the lab. Elizabeth is caught on the videotape.
Mr Tesslar finds science equipment has been tampered with, and declares the lab will be locked from then on.
Toby produces a pheromone compound to make the guys irresistible to the girls.
Toby throws a beach party for Bianca's birthday. Elizabeth is not invited, and makes a storm at the beach using electromagnetic waves on the clouds.
Toby creates a robot Dina, so she can be on her date with Sean and work her shift at the same time.
Russ breaks Mr Tesslar's car headlight, so Toby creates some invisibility paint until they can fix the headlight.
Toby creates an organic growth accelerant for Dina, after Elizabeth makes Dina's hair fall out. The organic growth accelerant results in Dina growing a beard.
Elizabeth frames Dina vandalising Mr Tesslar's car, in the hope she will be demoted as Class Rep.
Elizabeth teams up with Garth to put some muscle into her plans.
Elizabeth and Dina both run for Class Rep. Elizabeth uses anti-friction spray on her competition, putting Dina in a dangerous position.
Toby tries to prove he is a genius by creating an anti-gravity machine, and fixing it to the school's ride on lawnmower. Elizabeth sabotages Toby's plans to make sure no one finds out they are both geniuses.
Toby and Elizabeth become scientific geniuses, after being zapped by a scientific ray gun, called the MFE. Elizabeth interferes with Toby's first experiment, cloning a T-rex.
