The prospect of a normal life dangles tantalizingly for the occupants of the runaway Moon when they find a new solar system with a potentially habitable planet that Bergman identifies as Ariel. For a while, the crew are able to experience real air, warm sunshine and the hope of a new Earth. Paul Morrow and Sandra Benes contemplate the possibility of a normal, loving Earth-bound relationship. But some strange discoveries on the surface of the planet soon shatter all the dreams of the future.
As a pair of reconnaisance Eagles approach the planet Ariel to check the suitablility of the planet for colonization. An alien object from the planet is detected. It is on an intercept course for the two Eagles. It is believed to be some sort of missile. Unable to outrun it, it follows, then attaches itself to, Eagle Two, but does not detonate.
A launchpad and the surrounding area is cleared and the device is brought back to the base. When it is determined to be realtively safe, it is brought inside for examination.
Victor examines the object and cannot tell what it is. Koenig theorises it is a mystery devised by the people of Ariel to stall the Alphans from approaching the Planet. When all of a sudden the device starts expelling a gas at an astronomical rate.
The area is evacuated and the airlocks opened to release the gas into the vacuum of space. Back in Main Mission, a fleet of small probes are spotted landing on the Moon's surface. As Koenig prepares for what is surely an invasion, Victor announces that the unknown gas has turned out to be air.
Ariel's sun rises over the Moon creating a red sunrise and a blue sky. The Moon has been given an atmosphere! Their search for a new home might be over. Now they just have to check that the atmosphere is safe for them to breathe and live in.
When Helena has run all the tests she could, and it appears safe, Koenig asks for volunteers to go out and test it. Everyone wants to be the first, but Paul and Sandra are the ones chosen. They go outside, open their helmets, and enjoy a breath of fresh air.
Though everyone is ecstatic at this developement, John is worried that they will not be able to sustain life on the Moon without water to grow crops, and thinks that they should focus their efforts on exploring Ariel. The probe comes back to life, and causes it to rain.
With the promise of rain, and the threat of Alpha being at the bottom of a circular lake, an expedition, under Doctor Russell's command, is sent out to search for the best place for the Alphans to settle on the surface.
They quickly realise that an atmosphere is both a blessing and a curse, when their communications are disrupted by weather conditions. The Eagle is hit by lightening and crashes. Helena, Paul, Alan, and Sandra are stranded with no means to communicate with Alpha. The food and water stores are contaminated by an acid leak, and Sandra is suffering from a concussion, both caused by the crash. To make matters worse, the downed eagle is being buried by moondust.
Koenig, sends out the remaining Eagles to search for them. Then Kano reports that several of the eagles are grounded due to corrosion.
Victor discovers that parts covered in a graphite compound are not being corroded, so they decide to strip an Eagle and coat all the parts with it.
Meanwhile, Paul discovers an alien food source on the surface while searching for water, and builds a shelter for Sandra.
After discovering that Paul had already eaten this food, Helena suggests they test it before they all do. It appears to be safe with the limited tests she can run, but Paul starts to act strangely.
Back at the base, Koenig learns that the Moon is not going into orbit around Ariel's sun. The probes return to remove the atmosphere so it does not turn into ice and crush Alpha. The retrofitted Eagle is completed and Koenig heads out to find his comrades before the atmosphere is stripped away!
Paul freaks out when Alan throws away the alien food that is causing him to act so strangley. A fight ensues and Helena hears an Eagle approach. She runs to the Eagle and opens a few gas cannisters. She grabs a laser-rifle and, from a short distance away, she fires and blows up the Eagle. It is enough to draw the attention of the approaching Eagle.
Alan and Helena head back to Eagle, and John tries to help Sandra but Paul attacks him. Koenig knocks him out and they all head back to the base before the atmosphere is completely stripped away. One of the alien probes tells them that it was the absolute need of the people of Ariel to keep the Alphans from penetrating the atmosphere of their planet, as they have watched Earth since the beginning of time, and that Man's nature was such that they could not risk it.
The probe leaves as the Sun sets for the last time.
By raja99 on 27 Jan 2003 01:28:14 In my opinion, this episode does a wonderful job of summarizing many of the recurring themes of the series, and the last sunset of the ending is terrifically bittersweet.