The news of the aliens has leaked and been published in the press in New York. US Senator Anderson is involved. It is decided to not send Adam to New York for the time being. The Walshs' house is under siege by the press. It is decided to let Adam and Varossa stay in the school play house. Meanwhile, Peter has snuck out and is trying to contact the mothership via the "radio". They hear him but there appears to be some conflict going on and they do not reply. Professor Mayer flies to Sydney with his son Edward. Apparently a new male Soshun has been elected who says the aliens must come to live on Earth. This happened because the old Soshun wanted Earth to invite them to come. The flying saucer lands in the school grounds. The pilot hypnotises Peter and makes him enter the saucer. They leave.

A very rich man, Rudolph Lindenberger II, comes to see Professor Mayer and tries to talk him into letting him get some sort of access to the aliens for monetary gain. Mayer goes to Sydney with his son. Back in Sydney there are people protesting outside the Walsh home, some for the aliens, some against. The flying saucer with Peter on board lands on the aliens' moon. The pilot takes him into a room in a cave where the new Soshun is in charge. The old Soshun comes in and talks to Peter. She explains what has happened and that she does not agree with the new Soshun's plan about Earth. This is to invade Earth if need be. She says they have one weapon.

Varossa is taken to hospital. Colonel Nash's driver comes back and says he took Nash somewhere. This was really Adam, he too was hypnotised. Everyone leaves the Walsh house and they are followed by Linderberger's man Blake as well as media cars. Out in the bush they swap cars while Police pull over the media and Blake. Adam catches a train to Parkes. The car with everyone in it goes via Mudgee to Parkes. The Soshun says he wants to write a letter to the Prime Minister and will send it back with Peter to Parliament House. The Soshun sends his thoughts to Peter to put in the letter. They arrive at the Parkes Radio Telescope and Professor Mayer goes inside with Nash. A technician pulls apart the "radio" to try to discover the frequencies it uses so they can use the telescope to talk to the Soshuniss moon. The telescope is used to find the moon and seems to locate it.

Defence authorities in Australia have located the satellite Soshuniss using the Parkes radio telescope and Mayer is shocked to learn nuclear weapons will be used if hostilities arise. Adam communicates to Jean through a dream which directs her to a post office in Bunyul, a deserted mining town outside Parkes. Jean decides to sneak out of the Parkes compound and find Adam. Meanwhile Peter has been left comatose in the courtyard at Parliament House with a letter from the Soshun. This is taken to the Prime Minister's office while Peter is taken to hospital and then Sydney. Jean locates the post office and inside the postmaster has a letter for her. The letter has a map and instructions that Adam is hiding in a shed at the Bunyula Showground. Bernie and Edward meet Jean and they locate Adam's hideout.

Lindenberger's henchman attempts to steal Adam's communication device from Professor Mayer at gunpoint, leading to Blake chasing Bernie across and over the radio telescope's dish. The dish is tilted right over so Bernie can step off while Blake is left hanging vertically at the top. Bernie runs away and returns the device to Adam who attempts to contact the Soshun. Mayer and the other children go to Adam too. The flying saucer receives the signal and is heading towards them. Blake is let off the dish and finds Adam. He tape records Mayer explaining that Peter was returned to Earth in a coma with a hostile threat from the Soshun and that the radio telescope is now being used to track Shosuniss so that it can be destroyed. Meyer volunteers to visit Soshuniss to act as a human shield in case of an attack from Earth. Adam also reveals that only a Soshunite scientist can bring Peter out of his coma. Blake goes back to Lindenberger with the tape recording.

Colonel Nash takes the wounded Mayer and Adam in his car to Lindenberger. Mr Walsh sneaks away and arrives in Canberra demanding a meeting with the Prime Minister advising that the weapon that the Soshunites have is their moon. They intend to smash it into Earth if they are not given a place to live. Adam contacts the Soshun again and tells them to destroy the radio telescope. The Soshunites use radio or sound waves to damage the radio telescope and prevent it from tracking Soshuniss. Adam and Dr Kamutsa, a representative of the Secretary-General of the UN and some others meet with the Prime Minister. The UN has delegated the role to negotiate to the PM. Adam uses the radio to speak to the Soshun and pass on the PM's request for a representative to visit the Soshun to discuss "a peaceful and harmonious end to this squabble". The Soshun advises he will negotiate only with the children, Jean, Bernie and Edward.