Season 1

A mysterious stranger appears on the doorstep of the Walsh family's home one stormy evening. With no memory of his own name or how he came to be there, the family shelter him for the night and he assumes the name Adam Suisse. Impressed by his advanced linguistic skills and intelligence, Mr Walsh offers Adam a teaching job. His teenage children Bernie and Jean, along with their friend Peter Cannon, discover a strange communication device among Adam's possessions.

Adam is away bushwalking in the Blue Mountains and the children break in to his room again. They find books that they think are strange. He comes back and later, he asks if they broke in. They say yes. He explains the books and says the device is a radio "for local broadcasts" and he has left it in the mountains where he stays. Bernard, one of the children says that flying saucers were seen at "Canley" in the Blue Mountains the last weekend. Adam says he did not know this. The next weekend he goes to Canley again. The children follow him on the next day's train. They are going to watch him. They go bushwalking and find labels from books from their school. They come across Swiss and then find a flying saucer ahead of them. A man comes out, sees them and shouts out to Adam in a strange language.

The children encounter Adam outside the flying saucer. Adam admits that the "machine" comes from his homeland. He admits he has not lost his memory but he wanted to live amongst them to learn things. He brings out the man from the flying saucer and says he is the pilot, Varossa. He then uses a form of hypnosis to convince the children to come with him to his homeland. They all get in the flying saucer. The next thing the Mr Walsh has reported the children as missing and the Police say they are just hiding. Mr Walsh receives a letter from Jean, postmarked Venezuela, in which she says she cannot explain what has happened and will return but she is not sure when. The letter was posted the day after they disappeared and took only four days to get to Australia.

The children are now on the moon and meet some of the survivors, including the female leader, Soshun. Soshun reveals that Cinchy (spelling?), Adam's real name, will take the children back to Australia with Varossa. After the children leave her presence, Soshun talks to the elders in a way that implies some menace to Earth. They all return in the flying saucer and when back home, the children tell their parents about what has happened. They do not believe them. The Police arrive and question the children and the aliens. Suisse advises he does not know how old he is as they have no concept of years. Adam and Varossa are arrested. Mr Walsh contacts Professor Mayer who speaks to the children. He advises that he will make arrangements so that the children can secretly take him to the flying saucer.

After taking off in the flying saucer, the children contact the Soshun and speak to her via a video phone. They tell her what has happened and ask for her help. She sends a guide ship to them. Meanwhile, the two Police contact their superior who contacts the RAAF. The Captain advises the saucer is not theirs and they will act. The RAAF buzzes the flying saucer with jets. The Police advise Mr Walsh what has happened and that the security forces are now involved. The guide ship arrives. A pilot is transferred from the guide ship and takes over. The pilot cannot speak English. The RAAF pilot advises the Captain that they lost the two ships at 54,000 feet. The Professor and the children meet the Soshun and advises he will write letters for the children to post once they return to Earth. These will, he says, explain everything.

Bernie hides Adam and Varossa in the school's tower. The flying saucer lands at Idlewild Airport (looks like it was really the ABC Gore Hill property) and Professor Mayer gets out. He is taken away by some people in a large American car with UN stickers and the saucer departs. The children are questioned by the Police and Colonel Nash to find where Adam and Varossa are hiding. Professor Mayer is taken to the UN Headquarters in New York and presents the case that the aliens be permitted to land on Earth. He advises that they want to share their knowledge with all nations. Mayer phones Mr Walsh and speaks to Bernie, saying he must stop the aliens leaving in the flying saucer. It arrives to collect them and Bernie and Peter tell Adam and Varossa. The saucer leaves without them. Two Police officers pass them all over to Nash and the Chief Inspector. Nash advises that Adam and Varossa will be sent by plane to New York.