Having said that, I hear the show usually sucks. I wouldn't know. I've only seen one episode and I liked it.
The episode I saw was narrated by Stephen Hawking (yes, the famous professor) and directed by Jonathan Frakes, who was in Star Trek: The Next Generation. Although I'm sure he didn't play a Vulcan, I think he served in some capacity similar to Spock's. Whoever he is, he's a hell of a director. I didn't have much faith in a TV show like this (after all, it aired on ABC and I don't like TV very much), but its production value was just as good as any Hollywood movie. It starred John Hurt, whose character has two heads, and Brian Dennehy, who has a gigantic, muscular left arm.
You know what? The acting is top notch. I'm not kidding. A lot of boring people might snicker seeing these actors surrounded by whacky special effects and makeup, but Hurt and Dennehy take their jobs very seriously and I really respect that. A lot of actors would have written this off as nothing more than a paycheck in a silly genre.
The Discarded refers to a group of mutants who have been quarantined from Earth on a giant spacecraft. Life sucks for them. Some get so stir crazy, they kill themselves and the crew has to dispose of the bodies. One day, a ship from Earth makes an unscheduled rendezvous with the discarded's spacecraft. A man boards their ship and tells them that after they were discarded, the virus that caused the mutations in the first place evolved and came back with a vengeance. Their only hope for a second cure lies in the enzymes manufactured by those who were originally infected - the discarded.
And that's all I can tell you. You have to watch this forty minute show. It kind of makes me wish I had a second head. And a giant arm. I don't know so much about the whole living-on-a-spaceship thing, though.