The Curious is inside a cave in a forest, using a wooden spoon to make music. The narrator raises the possibility that everything The Curious does is connected.
Thomas is upset that he had to move to the countryside with his mother and misses his old friends from London. His mother is making him hang out with Spud; the annoying son of his neighbours to try and find Thomas a new friend, however Thomas was paired up with Spud at school and the boys did not get on well. The boys explore the woods and find what Spud thinks is a bomb crater but Thomas thinks looks more like something crash-landed there. Sure enough, there are mechanical parts scattered around. Thomas takes a piece of equipment which he assumes was an aircraft's black box, and decides to fix it so he can find out what caused the crash. The box begins emitting a signal and then stops. Thomas thinks it's broken, but is woken in the night by the box glowing brightly. Spud comes to the window and alerts him that there's a bright light in the woods, convincing Thomas to go down there and check it out.
The boys discover a suited figure inside a capsule, which Thomas recognises as an escape pod. Just as it dawns on him that it came from an alien craft, Spud plays around with the control panel and opens the capsule. An alien comes out and chases after the boys. They run to Thomas's house and alert his mother, who goes outside to look. The alien comes into the house and the boys panic, but realise that the alien is a child their own age. The alien asks for their help to contact his parents and return to his own planet. He needs a transmitter which was lost from his spaceship; from a description, Spud works out that it crash-landed onto a cliffside.
The boys go hiking to look for the transmitter. Since the alien's real name is impossible for humans to understand, he asks them to give him an Earth name, and Thomas chooses Stan. Stan begins to have difficulty breathing and says that his life support is failing. He needs to contact his people urgently. The boys find the transmitter, but it is on the top of the cliff far above them. Thomas climbs up to grab the transmitter while Spud complains to Stan; he is hurt that Thomas, and the boy who lived in Thomas's house previously, both rejected his friendship. Stan says that he and Thomas understand each other because they are both far away from home. He communicates via the transmitter and climbs into his capsule, preparing to return home.
However, Spud presses another button on the capsule, which translates Stan's communication into English. It reveals that he came to scout Earth for an invasion, and is now telling his own people to follow the signal from the pod and annihilate the planet. Thomas and Spud confront Stan, who tells them not to feel bad that he tricked them, and points out that he never said he was a harmless child - they just assumed it. Spud tricks Stan into launching the capsule far into space, where the aliens won't find anything to destroy. Thomas happily declares that Spud is his best friend. They ponder what Stan will do now that he's stranded on earth forever, and Thomas suggests that Stan could blend in since he looks human. Stan angrily removes his breathing apparatus to reveal that he does not have a mouth.
As the narrator cautions the audience to question their instincts and whether one's friends are really who they say they are, The Curious digs in the forest and takes the transmitter Stan left behind.
This episode contains examples of:
- And I Must Scream: Stan is forced to remain on earth, unable to ever be found or return to his own planet. What's worse, he quite literally doesn't have a mouth so there is no chance of him living life as a human as Thomas suggested.
- Big Eater: Spud, who likes to eat potato chips.
- Cat Scare: Thomas's mother is spooked by a cat when the boys claim something outside was chasing them and she goes to investigate.
- City Mouse: Thomas has recently moved from the city to the country.
- The Farmer and the Viper: The moral of the story.
- Human Aliens: Stan, although it's subverted by the ending.
- I Just Want to Have Friends: Spud desperately wants to have friends but is constantly rejected.
- Sarcastic Confession: Thomas does this when his mother asks why the boys are going hiking.
- Trademark Favourite Food: Spud's fixation with potato crisps.
