After a year's fruitless quest to find the adults, the Sparticles find the key that they have been carrying for so long fits into a clue. However, they are forced to play a ruthless game in order to be able to attempt to get the key to fit in.
The episode starts off with the Sparticles being chased through a football stadium. It is revealed that they were led to the stadium, which is owned by Fizzy. A boy starts to search the tribe for the key Doomsday Dora gave them. Fizzy then emerges with an older girl with a crown on his head. Fizzy remebers that they stole the train and it is revealed that the girl beside him is Flora, the former leader of the tribe of girls that stole the Hotel off the Ranchers. It is also revealed Fizzy and Flora have stolen other treasures, including The Crown Jewels, and that they have spies. They mock Reese about her powers, make her and Sadiq clean Fizzy's trophies and make Frankie clean the toilets.
Holly is taken inside the stadium where she is revealed to be the mole who tricked the Sparticles into going to the stadium. Despite her betrayal of the Sparticles, Holly is put on dinner lady duty. We learn that has been a year since the incident at the Sparticle Project and she is betraying her tribe as she does not want the adults to come back.
Back on the pitch, Reese and Sadiq are cleaning Fizzy's trophies. Reese tells Sadiq that she used to go to all the home games in the stadium, as she and her parents had season tickets. Sadiq then plays with the World Cup trophy (one of Fizzy's other treasures) but is told to stop.
Holly puts laxatives in Fizzy's gang's food to make desperately them need the toilet. The laxatives start to take effect, to Holly's mingled amusement and disgust - even Flora is unable to stop herself from farting loudly - and moments later they all run off to go to the toilets. Frankie, who has just finished cleaning the them, watches the boys rush in surprise. Frankie is encouraged by Holly to grab the keys off the distracted boys and runs off with Holly and locks the main door into the toilets.
Outisde, Serena is looking at a stone head with two keys similar to the one the Sparticles posses in a stone head while Serena makes Sadiq polish the head while Holly and Frankie run from the boys. Sadiq then spots the key in a glass case and calls Reese, but she is distracted. Using her powers, she has made her parents appear beside her, but they cannot see her in between them and Sadiq cannot see her parents either. Meanwhile Holly and Frankie are trying to escape. While Reese explains to Sadiq that she saw her parents, Sadiq tries to convince her to look at the key when Holly and Frankie burst in. Sadiq breaks the glass to get the key and then runs, trying to convince Reese to come but she refuses to move (not wanting to be parted from her parents) and is grabbed by some boys. Sadiq grabs a key from the stone head and runs, leaving Reese behind. He gets in the Sparty Van while Reese is put in a cell.
They other three are driving along to get the other Sparticles, while Fizzy claims he is going to destroy the Sparticles while Reese is in the cell. Whilst in her cell, Reese as a vision of Serena in a surgeon's uniform. She then tells Serena that she wants the adults to come back, as she wants to be a surgeon. Serena then tells Reese that Fizzy trades on real and imagined fear.
Sadiq then goes into a clinic to get Tia who is now a nurse and informs him that Ami and Jordan have gone to France on a yacht. Jeffrey is also working there and he, Tia and another girl try to fix a dislocated elbow. Liam is also there and Sadiq shows them the two keys that fit into the head and convinces Tia, Jeffrey and Liam to come with them.
Sadiq and Fizzy then proceed to fight until Sadiq makes a bargin. If the Sparticles win the 'Fizzy games', Reese goes free, they get the keys and they get one other prize but if Fizzy wins they get none of that. Meanwhile, Callum who is now a 'sheriff' under Fizzy's rules, sees a poster for these games and stows away in a cart headed for Fizzy's stadium.
In the stadium, Reese is forced to sit on a slide that leads to a hatch on the top of a shipping container. If the Sparticles fail, she will be forced down the slide and into the container, inside which is a lion that has not eaten for a week. Callum, who has got inside the stadium, is watching from a seat. The Sparticles and the Dims (Fizzy's tribe) head onto the pitch while Fizzy announces from a booth along with Flora. Reese calls out for help from above the box. They line up at the start. Frankie then crawls through a tunnel full of rats, which is followed by Liam going blindfolded through barbed wire tied into sections by tires. Tia then goes under a shower of mealworms followed by Holly having to eat three sheeps eyes (much to her disgust). Sadiq then gets into a sumo suit and proceeds climbs up a inflatable ramp, but he is pushed down by a rival (to which Callum claims quietly to himself is a foul). Sadiq manages to climb up the bouncy castle, but the line is cut by a Dim and Reese uses her powers to broadcast her thoughts claiming they cheated. She also reveals there was no lion - the image of it (that was supposedly inside the container) on the screen is fake and the sounds came from a radio. Reese then gets the key while Floras bag catches fire (thanks to Reese messing with the electrics in the stadium), which Fizzy puts out with a fire extinguisher. Callum then rushes down to greet the Sparticles and reveals Kat is sorting out the nuclear power stations. The Sparticles then proceed to run across the pitch and they insert the key into the stone head but nothing happens, much to the Sparticles disappointment and Fizzy's joy.
The Sparticles are then thrown out of the stadium along with the stone head. Liam notices the head has writing on the neck and theorizes that the head could have a clue to the Quantum Nexus and they decide to head to the museum where the head belonged. Most of the tribe agree to this but Holly disagrees. Reese then notices the Fizzies (money that Holly was given as a reward for betraying them) in Holly's pocket and realises that it was she who betrayed the tribe and that Fizzy paid her to lead the Sparticles to the stadium. Holly is then kicked out and declares in response she is going to make sure the adults do not come back. Holly then teams up with Serena (who claims she has been sent by Fizzy to keep tabs on the Sparticles) to stop the Sparticles and leaves in Serena's pink jeep. The Sparticles proceed to The Sparty Van to stop Holly and Serena.
- At the start of the episode, the subtitles read "lead" instead of "led".
- Some of the sound effects are missing from the opening titles.
- Ami and Jordan's absence is explained that they have gone to France.
- Kat's absence is explained that she travelling around the country shutting down nuclear power plants.
- First appearance of Serena.
- The end credits now scroll up n the middle of the screen instead of appearing and vanishing.