"The Backyardigans love making socks at the sock factory, but after an accident, they must venture into the giant sock machine itself to save socks for all of humanity."
Uniqua, Pablo, Tyrone, and Tasha are in the backyard sitting on the picnic table near a bucket full of socks. Tasha tells the others that a pair of socks is coming down the line. Pablo makes sure the socks do not have any static cling. Tyrone makes sure that the socks are a match. Uniqua folds them and places them in another bucket. Tasha greets the viewer and introduces herself as Foreman Tasha. Uniqua introduces herself as Folder Uniqua. Pablo introduces himself as Static-Tester Pablo. Tyrone introduces himself as Sock-Matcher Tyrone. They all sing "Socks, Wonderful Socks".
Tasha tells the viewer they work at the sock factory, where a large invention known as the sock machine creates all the socks in the world. They hear the sock factory whistle. The backyard transforms into the sock factory. The characters repeat what they did in the backyard. Tasha uses a pencil to write on a clipboard. The four sing "That's My Job, That's My Job" as they explain what job each of the characters own. Tasha accidentally drops her pencil into the sock machine. Pablo tells Tasha that a tiny pencil like hers probably could not hurt a big machine like the sock machine.
The machine starts to malfunction. Socks are shot out everywhere. Pablo tells Tasha that he could be wrong. Tasha tells her workers that she will get her pencil from inside the sock machine so no more damage is caused. The three others follow her in the machine. They examine the many gears inside the machine. Tyrone tells the others that in all his years, he has not seen anything like the sock machine. They see the pencil go inside another room inside the machine. They follow after it.
They walk into the Static Cling-atron, a machine that prevents socks from clinging together by using powerful air to blow them apart. Pablo is amazed. The pencil is blown up and hits a part of the machine. Pablo says that a small pencil probably could not hurt a big machine like the Static Cling-atron. The machine malfunctions and the air gets more powerful than ever. Pablo says he could be wrong. Tyrone is pulled off the ground. Uniqua holds on to his foot and is pulled off the ground as well.
Tasha grabs on to Uniqua's foot. Pablo grabs on to Tasha's. Tasha tells Pablo to stick the socks together with static cling to create a rope, which they can use to reach an air shaft. Pablo tells Tasha that his job is to do the opposite. Tasha forces him to do it. Tyrone grabs on to the shaft and brings the others up. They walk into another part of the machine. Uniqua asks Tasha what would happen if they do not retrieve the pencil. Tasha tells Uniqua that that could mean the end of "sock-ilization".
The four sing "A Life Without Socks Is Not a Life for Me" as they discuss what would happen without socks. Tasha spots the pencil going into another door. The foursome enter the door and discover a sock decorating machine. Tasha spots the pencil once again, but she does not have enough time to retrieve it before it damages the gears. The controls go out of control. Smoke comes out of every machine.
The cast rolls, trying not to get crushed by anything. They zigzag when trying to escape colorizers. They finally reach the exit and stand still. Uniqua notices that a giant metal container is about to crush them, so the four jump out and tumble. They get back on their feet and gasp.
The Giant Ball of Yarn, a huge ball of yarn used to make every sock in the world, is floating in the center of many floating platforms and shelves. The futuristic platforms take socks away. The four are amazed. Tasha sees the pencil and asks how they can get down to where the pencil is from where they are standing. Uniqua reveals to them that she had been working on a fold called the unbreakable fold and performs it. She hands each of them a pair of folded socks.
They slide down fragments of yarn using the folded socks. They sing "Gotta Get the Pencil" as they try to grab Tasha's pencil out of mid-air. The pencil falls into the Giant Ball of Yarn and a rumbling sound is heard. Floating platforms fly everywhere and socks are flung in every direction. Tasha spots an "off" button. In slow-motion, she yells "For the love of socks!" and pushes the button. The platforms and socks fall to the ground. Uniqua, Pablo, and Tyrone celebrate.
Pablo hears a noise and thinks it is a another pencil stuck in the sock machine. The noise is revealed to be coming from Tyrone's stomach. Tasha invites everybody to her place for grilled cheese sandwiches. The sock machine transforms back into the backyard. The children sing the end song. Tasha backs up and shouts "For the love of socks!"