Five and Six are in the gym about to do a tricky jump, but Three slips in and nearly ruins things for them. After complimenting her friends on the jump, she then tries to say hello to Four in the Cosy Room. Unfortunately she ruins the game he was teaching to One. Three then starts to feel unwanted, but that doesn't last for long because the alarm went off and she, Four, Five and Six regroup in the Control Room.
Two had been the one on duty, and quickly goes off to play once the bigger Numberjacks attend to the call. Agent 25 reports the problem: a car had a wheel missing. Four says he should sort the problem because it's a problem regarding the number four, but there were three wheels, so Three says she should sort the problem. Five and Six say they can both go, and Four promises to look after Three.
Once in the launcher room, Three asks if she can go first and Four accepts, probably as an apology for being snappy at her in the Cosy Room. But, there's a catch: the launcher breaks just as Three had left, and Four has no choice but to stay behind and fix it.
Both Six and Four are a little anxious about Three being on her own, and even Three feels a bit worried once she learns the news, (maybe due to being caught by the Puzzler in The Container Drainer when she left Five's side). But, she gets the nerve to go and find the car. Five realises the problem is because the car only had three wheels, but Three feels the car could somehow work with three wheels.
Agent 34 reports another problem at the cafe. Six thinks it's the waitress folding the napkins, but the problem was actually a table leg going missing. Three arrives just in time to see a chair leg go missing too. Agent 88 and Agent 100 realise the problem: there should be four things, but there's three things and it doesn't work. Three is offended by this claim, and Six gently tells her that three isn't working as well as four at the moment. This is when Three spots the meanie of the episode: the Shape Japer.
The Numberjacks then learn that the Shape Japer is making fun of threes because they aren't working. Just at that moment, Four shows up, saying he's having no luck with the launcher, and the agents realise that the Shape Japer likes fours becasue she's a square today. Three goes after the Japer and is confident she'd find things where her number works well, and Four gets back to mending the launcher.
Three, Five and Six start looking for threes at the school sports day, but instead they find lots of twos and fours. Agent 88 manages to find a buggy with three wheels and agent 100 finds a three legged stool, and Five locates the three-legged race. Three then spots some sandwiches cut into triangles, and gets the idea to make more triangles. Six fires the brain gain, and Three sucessfully makes triangles out of three straws and three children laying on the grass. The Shape Japer finds a picnic rug and is still going on about fours, but Three gets the idea to fold the rug into a triangle. Five remembers seeing the napkin being folded in the cafe, and Six quickly fires more brain gain. Finally, Three turns the Shape Japer into a triangle, and Four comes out, having fixed the launcher. Three flies back home, and Six is very impressed with her first solo mission and they review in onscreen.
Later on, Four, Three and Two are playing Piggy In The Middle, but Two rolls the ball the wrong way. Three quickly goes off to get it, but wonders what would happen if the picnic rug was to be folded again, giving the challenge to the viewers as the episode ends.
This episode provides examples of:
- Loud Gulp: Three gives a nervous gulp when she discovers that Four can't do the mission with her.
- So Proud of You: The way Six praises Three when she's back in the sofa definitely gives off this element.
- Wham Episode: Three and Four are going on a mission... wait, Three's out on her own? What?!
