The Fallout is tenth episode of the first series of the Sparticle Mystery and it was originally broadcast on March 1st 2011.
Holly realizes that the journey is almost at an end, which causes her to fall out with her fellow Questers and she ends up locking everyone but Sadiq and herself in a bunker controlled by a computer that thinks theres been a nuclear fallout and wont let them out, can she and Sadiq save them?
Meanwhile the tribe of girls that the Ranchers invited into the hotel are becoming increasingly hard to tolerate.
The Questers have stopped in a field and are relaxing, Jordan is talking with Jordan and Ami while Reese is studying a sunflower with a magnifine glass. Reese meanwhile annoys Holly which Kat notices but Reese runs off. Holly spots Reese and follows her through a bush, causing her cardigan to rip. Holly finds Reese going down a lift. Ami and the others spot Holly while Reese explores the tunnels the lift has led down into. Everyone but Sadiq goes into the lift and they explore and stumble upon some bunny ears Reese was wearing. Sadiq is meanwhile packing up the Sparty van.
Down in the mine they stumble upon a room full of wires and switches and find Reese messing at it, the room turns out to be an old telephone exchange. They go and explore some more, Holly going off in a different direction to everyone else. Holly finds some old bedrooms while Ami and Jordan find tinned food and other supplies. Reese finds Holly. Kat finds Ami and Jordan and explains that this is a shelter in case a nuclear fallout happened. Reese figures out that Holly wants the Quest to fail, causing Holly to throw a photo frame at her and to storm off claiming that they always side with Reese.
In the hotel, Jeffrey, Liam and Frankie prepare to go to market while the girls laze around, using the avacados and cucumbers for facials and that they also used the hot water when it was Tias turn to. They give Jeffrey a list for the market much to his annoyance.
Holly leaves the bunker, unwittingly traping the other Questers down in a bunker. Sadiq and Holly talk about the adults disappearing for a reason. Holly reveals she trapped the others down in the bunker while Kat and the other Questers prepare to leave. They come to the lift and find they're trapped when a computer, N.A.N.C.I (Nuclear Attack Network Contingancy Infrastructure). N.A.N.C.I believes that there has been a nuclear attack when in fact it was the Sparticle Project.
At the market the Ranchers are trading at the market seen in the previous episode while Tia notices theres less stuff to trade with and she is starting to get annoyed by them. When they return to the hotel, the girls are clearing everyone else possessions out of their hotel rooms. Jeffrey, meanwhile is in the kitchen trying to discuss things with Flora about she and her tribe being lazy but she is proving to be disagreeable.
Kat, Jordan, Ami and Reese are trapped down in the bunker, trying to escape. Kat gets the system to measure surface radiation levels, which are nil but N.A.N.C.I still believes there has been an attack. Sadiq meanwhile desends into the bunker.
Jeffrey is meanwhile transfering plants from his garden into mobile containers as the tribe of girls is just to big to fight against. Despite Liam and Frankie protests they still plan and agree to leave in the end. They collect all the remote control cars and old food they can. Jeffrey meanwhile acts the tribe of girls do.
Down in the bunker, Sadiq is searching for the others while Kat and others confer on how to get out. Ami and Jordan have an idea to literally drive the computer insane by asking it questions after Kat compares it to the smartest adult but even smarter. They ask it questions and drive it insane with questions such as "What is the meaning of life?" or "Why is my hair curly.". They temporarily shut it down as its rebooting and they come across Sadiq while trying to escape but N.A.N.C.I catches them in the lift, Reese yells "Help us." to Hollys mind, who is on the surface. She breaks into the bunker while the others down in the bunker try to find a way out but just end up running in circles. Sadiq breaks a bit of N.A.N.C.I casuing some of the lighting to turn off. Holly the comes on a cart to pick the others up. They escape with some supplies including torches.
Meanwhile, the Ranchers leave the hotel much to the other tribes surprise, saying that they need them but Liam retorting "We dont need you!".
The Questers meanwhile sparypaint the door of the bunker warning others about the computer system in the bunker. Holly and Reese argue again before leaving the field they were camping in.
Meanwhile the Ranchers have secretly lay some traps including putting rotten food in sevral locations, playing classical music over some loud speakers and making the remote control cars race around and shutting down the electricity as they took the lumminite as well. Tia starts crying as they've lost the hotel and they leave with Jeffrey saying they'll find somehwere better.
It finally shows a view of the door with the warning and the voice of N.A.N.C.I, which has completely overloaded.
- This is the last episode where the City Hotel is seen.
- What happened to most of the tribe of girls is unknown however Flora is known to have sided with Fizzy as seen in the episode The Stone Head.