In the gym, Six is trying to convince a reluctant Four to practice jumping with him. Four is on a machine that has flashing lights coming from in front, both sides, and behind and the object of the game is to jump on the lights. He does well at first but misses the flash from behind. Six then tries and wins despite using a harder version of the game that also includes lights from above and below.
The alarm sounds and the Numberjacks arrive at the control room, with Three running late. The relatively minor problem (not that that pacifies Six) is that the bottoms of two of a young girl's boxes have disappeared, making the contents spill out. Six feels that the mission is best suited for either himself or Five, so she sends him.
Six is launched (with Jasper watching) and lands on a child's foam puzzle. The Numberjacks ask what boxes need, and the agents reply that boxes need four sides, a bottom, and a top. Agent 101 then reports another box problem: one man's box is oddly shaped.
Four doesn't see the problem, so everyone else points out that the boxes' strange shapes make for poor stacking, and sure enough, the man is having trouble stacking his boxes. The culprit turns out to be the Shape Japer, who causes one woman to spill her sports balls, another to spill her sugar cubes, and a third's cardboard box to change shape.
Three and the agents use brain gain to turn the boxes back to normal, and this works, but then Three keeps making brain gain even when it isn't needed, resulting in a meal, a soccer ball, and a man being put into cardboard boxes. Five imagines a snake, traffic lights, and a tree being boxed.
Three suggests using more brain gain, but Four has lost contact with Six. Four searches and finds a yellow box, which the agents suggest he may be inside. It turns out that he is, so they use brain gain to take the yellow box apart. Three makes more brain gain and makes the other unwanted boxes disappear. The brain gain also zaps the Shape Japer, making her groan and fly away.
Six returns, Three and Four apologize for the extra boxes, and they recap the mission. Then, Four notices that it's unusually quiet. Turns out that the quiet is because Three isn't there... but a box is... which Three pops out of to scare the others. Five asks the viewers to find boxes around their house.
This episode provides examples of
- Alternate Catchphrase Inflection: Three usually says, "But not for long!" in a singsong, almost cocky, voice. Here, she says it in an out-of-breath voice due to having been running.
- Distressed Dude: Six and a random man end up trapped in boxes.
- Foreshadowing: The yellow box can be seen before Four finds it, hinting that Six is in there.
- It's Quiet… Too Quiet: Subverted. Four thinks it's too quiet and it seems like Three has disappeared or been boxed, but it turns out that she boxed herself on purpose as part of a prank.
- Product Placement: When investigating the little girl's boxes, some LEGO bricks are scattered near Six.
- Pun: Three jokes that she's a Number-jack in the box.
- Slapstick: The Shape Japer makes a girl and two women drop things.
