A new student arrives at Sandy Bay School, Jack. His only wish is to discover Elizabeth and Toby's secret. Elizabeth has turned Toby's cousin Sasha and Russ into flies. Will Toby come to her rescue when she's held by a giant koala?
Elizabeth's experimenting ends up making Sasha's teeth fall out in the bathroom sink. Thinking Garth will leave her as her sidekick Elizabeth causes him to grow breasts until he joins her for good. Will Elizabeth ever learn?
When Toby wants to get into the swim team to impress Niki, he makes a formula that makes him swim like a fish. But what will happen when Elizabeth finds out
After Elizabeth gets a deadly fever from Verity, she must do eveything anyone ask when needing help. Soon finding out that she could die she requires Toby's help. Will Toby save her?
Toby ruins Niki's project and his friends try to help him win back Niki by impossing as toby and giving her a new one. But Elizabeth notices something is up.
Russ is convinced he is a loser, so Toby helps by building a time machine so Russ can see his heroic ancestors. But it all goes wrong and Russ is time-swapped with a man from prehistoric times. Will Toby be able to save Russ?
Elizabeth is forced to move her gadgets from her lab temporarily. In a mixed turn of events Jack finds them. Now that he is closer than ever to Toby and Elizabeth's secret, what will they do?
After Niki gets criticized by her swimming coach, she tells Toby not to worry about it and says it's a confidence thing. Toby makes her a confidence ring, but when Russ puts it on, he refuses to take it off, until he loses it. Meanwhile, Verity wants to form a cheer squad to help win the swimming championships but keeps getting ignored, until she finds the ring.
Elizabeth zaps herself and Toby into a virtual reality game. Meanwhile Sasha gets reunited with her childhood horse.
Toby and Niki finally go on a date, but Elizabeth has a plan for them. Jack sees one of Toby's inventions and tries to get it for himself.
Toby and his friends discover a koala, whilst Garth's stupidity lands the enlarger ray in Jack's hands. By a series of events the koala enlarges and causes havoc across the school in a mist created by Toby? Will Toby and Elizabeth's secret come out? Will Jack act on his suspicions?
Sasha and Russ accidentally swap bodies after messing around with one Toby's inventions.They learn to appreciate each other's good qualities.
Elizabeth, hung up on Toby, blackmails him to go to the social with her and not Niki, whom he had already been asked by. Although, Elizabeth's blackmail device causes chaos when it falls into Jack's hands and she is forced to tell him their secret.
Because no one trusts Jack,he makes sure that Toby and his friends are all distracted so that he can take a peek in Toby's shed. But will he end up regretting this?
Elizabeth's tricks accidentally enable Sasha with extraordinary abilities to communicate with animals Dr Doolittle style.
After Verity does an experiment by a lake, the experiment goes wrong and Verity is slowly turning into an amphibious monster.
When Elizabeth goes to any extent to get information out of Russ, Jack finally gets evidence proving they are geniuses. Will he get away with it?
Toby uses his flying machine to help Russ, but doesn't know Jack is watching. Meanwhile, a dog-lover offers to donate money to the school. How will Jack try to blackmail Toby for the genius key this time?
Elizabeth creates a freaky machine to be her new assistant, but it becomes consumed with the idea that he must protect Eliizabeth and soon her safety is in danger.
Angry that Toby and Nikki are together, Elizabeth sticks Toby in a time loop, so he repeats the same day over and over again.
Once Mr Woods and Elizabeth are paralyzed by octopus poison, both Toby's side and Elizabeth's companions have to team up together to find an antidote.
Elizabeth gets revenge on a famous Hollywood actress who starts attending their school by playing a childish prank.
Garth's prankster cousin Rodney pays a visit. Whilst staying he manages to not only annoy everyone, but also turn into a half-man half-spider (Spiderboy).
Toby has to meet Nikki's parents. But Jack and Elizabeth have teamed up to make it a disaster.
Elizabeth decides to use Jack to make Toby jealous. All the while Jack is using Elizabeth to find out more information and to steal the disc.
Still love-struck, Jack talks Elizabeth into making Toby normal again. She agrees and goes off to perform it. While she is out of the way, Jack turns himself into a genius.