Inside its spaceship, an alien Marklar is preparing to land. It does so and encounters lions that kill it.
In a mission nearby, young Ethiopian boy Starvin' Marvin is asked to read a passage from the Bible as he and his fellow starving Ethiopians are made to worship Jesus Christ, follow the Bible and take Christian names under the false promise of food. He walks out and heads towards a crowd who stare over a mountain ridge at the lion that killed Marklar's spacecraft. Starvin' Marvin heads towards it and enters, accidentally launching it. After Starvin' Marvin's activity is discovered by the FBI, they decide to contact four American boys who had encountered him before. At school, two CIA agents tell Mr. Garrison that they need to speak to the boys.
After being tortured (by having to listen to balloons being scraped) Cartman finally explains who Starvin' Marvin is. Starvin' Marvin soon encounters the boys when his craft crashes into Cartman's house. They are then taken into space when the craft jumps into a wormhole and winds up on the planet Marklar. When they return, the CIA agents are waiting. The boys (except Kenny) manage to get back in the craft along with Starvin' Marvin and go back towards the planet Marklar in order to colonize it as a new home for the starving Ethiopians. The CIA manages to bribe Sally Struthers (who is now a Hutt) with Kenny's body. The Christian missionaries then realize they can spread the word of Christ to the planet Marklar.
Pursued by the CIA and missionaries, the boys have to figure out a solution. Cartman manages to convince Sally Struthers to leave them alone and to help stop the missionaries by appealing to her by saying that they're trying to be like her and simply helping these people. Using a cable channel to raise funds the missionaries are able to raise enough money for a starship, replacement engine, and a device to escape from Struthers's tractor beam.
On Marklar, the boys cannot convince the Marklars to let the Ethiopians stay due to the fact they cannot adjust to Marklar linguistics since the language refers to everyone, everywhere and everything as Marklar. Kyle manages to speak Marklar by giving his usual big speech but replacing every word with 'marklar' and the Ethiopians and Starvin' Marvin are allowed to stay. Meanwhile, the missionaries, and CIA are dragged away. The boys make an empty promise that they'll return to which Cartman says "when Jesse Jackson is President..."