After hunting for food, Masklin, a 4-inch-high (100 mm) Nome, returns to his burrow, and argues with his tribe elders about the lack of food and that they have no fire for heat. Masklin decides that a lorry might take them to a better place, but as he wonders, a fox attacks one of the elders, Mr Mert. Masklin chases the fox onto the motorway, killing both the fox and Mr Mert. Masklin decides right then they all have to flee.

The Nomes find a safe place at a department store, where they encounter several tribes of Nomes. Their story of being from the 'Outside' angers the Duke De Haberdasheri.

The Thing informs the Nomes that they are from another planet, that they arrived on Earth 15,000 years ago, and that they must return home to their planet. Masklin meets an inventor who shows them his inventions and is intrigued by the concept of 'Life Beyond the Store'.

Masklin and his tribe see the Abbott, leader of the Stationeri, who act as the Store's priesthood. On the way, they are met by Hardware bandits who are soon driven off. They meet with the Abbott, who does not believe them.

When the Abbott is alone with Masklin, he says that he has a number of concerns about the future of the Store. Many years ago, the different departments fought for control of the Store. It was only when the Sationeri asserted that Arnold Bros. wanted the departments to live in peace that the wars ended. If the Stationeri is proved wrong about the existence of 'Outside', the other departments may start fighting again. Therefore, the Abbott must pretend that everything is normal to keep the peace.

Charged by the Abbott for discovering the truth, Gurder takes Masklin and Grimma to the General Manager's office. As Masklin begins searching the desk, they discover a memo to the staff saying that the store will be demolished. They return to find that the Abbott has been talking at length with The Thing, and has reconciled his world view that 'Outside' is an extension of the Store. His final decree is that the Nomes must return to their true home, but dies shortly after.

Gurder presides over the Abbott's funeral, where it is revealed that he was chosen by the old Abbott to succeede him. Meanwhile, Masklin comes up with a plan to save the Nomes.

The Duke thinks Masklin's plan is foolish, and refuses to participate, but the other clans agree to work together, with the Stationeri (reluctantly) teaching many Nomes to read.

A Nome named Vinto, who tends to mistake fiction books for instruction manuals, reads about a hostage situation and suggests they could take a human hostage. However, Masklin doesn't think the plan will work.

The Duke is distressed at the disappearance of his son. Although he still does not believe in an Outside, he agrees to help Masklin, as he feels it might lead him to Angalo.

Angalo recounts how he escaped, and also that he learned how to drive a lorry. Vinto brings 'Gulliver's Travels' to Masklin, hoping to convince him to kidnap a human to help them, but Masklin instead sees the ropes holding Gulliver down; he believes they can use ropes to operate the lorry. Vinto discovers that, instead of the fortnight they thought they had, demolition has already started.

The Thing advises the Nomes to flee as soon as possible. Although demolition is still two weeks away, humans have started clearing the building and loading the store fittings onto a lorry. Dorcas tells Masklin that he has disabled the loading bay door so the lorry can't leave. The Thing tells Masklin there is an airport to the north and they should head to it, the it falls silent and leaves Masklin on his own. Masklin becomes overwhelmed by his task, but Grimma encourages him to lead the Nomes out of the store. The Nomes get into a lorry and begin to practice using the rope and pulley system Dorcas designed to drive the lorry. They start the lorry and begin to move, unfortunately they move backwards, not forwards, and crash into a petrol drum which tips over and spills. Prices Slashed comes to investigate, smoking a cigarette. Angelo tells the Nomes that if there is a single spark the spilled fuel will explode.

Prices Slashed sees Gurder denouncing the 'Demon', and is startled into dropping his lighted cigarette into the petrol. With no time to fix the door, the lorry crashes through moments before the petrol ignites and causes an explosion. They stop a short way down the street to see the store on fire. They drive off and, after a number of close calls, a police car begins pursuing them. The first scene of the first episode then repeats, this time showing Masklin and Dorcas cutting the police cars wiring while the Nomes in the truck hide. The lorry comes to a stop in an abandoned quarry near an airport. Masklin tells the others that they must move on at some point and try to get home. As they watch Concorde fly over, Dorcas remarks that it would be easier to drive than a lorry because it only has three wheels.