- The Control Voice: Contact happened exactly one year ago, and the world changed forever. The line between life and death was blurred, crossed... then totally erased. Not through divine intervention, but another force from the heavens. A force greeted not with rapture... but with fear.
An alien race comes to Earth and asks for permission to use human corpses as host bodies.
- The Control Voice: What if you were to wake up to a different world tomorrow... a world of invaders? Would you raise your voice with the aliens, in a chant of remembrance and regret, bidding farewell to a vanished world? Or would you fight against those who might ultimately help us?
The Second Trope:
- Benevolent Alien Invasion: Played with when the aliens are allowed to settle on Earth... and to inhabit the bodies of dead humans. The main conflict is between a character who can't accept the loss of the woman he loved, and the fact that the body's new occupant is in no way her.
- Doppelgänger Replacement Love Interest: Subverted. One man's wife dies and donates her body to an alien race (they can occupy and revive recently dead bodies, and need to do so to live). He meets the recipient, and finds out that they do sometimes inherit random memories from their hosts, but she does not fall in love with him, becomes bothered by his following her around and eventually gets a restraining order against him. It's even hinted that the process is set up to prevent the aliens from being close to family members of their hosts, presumably to prevent this from becoming a regular occurrence."If I look like her, if I sound like her, I might be her? The answer is no."
- Energy Beings: The N'Tal are symbiotic energy beings who cannot survive outside a host body for more than two years.
- Government Agency of Fiction: The Department of Alien Services.
- Human Resources: The N'Tal request that they be given dead humans as hosts since they can't survive in their own bodies for very long.
- Innocent Aliens: Since the N'Tal require host bodies to survive, they forge a deal with humanity allowing them to reanimate and take possession of the bodies of the recently deceased. Although Dr. Michael Alders, the Director of the Department of Alien Studies, becomes concerned that they may have an ulterior motive, it turns out that the N'Tal have been completely honest and straightforward in their dealings with Earth.
- Never Suicide: The best friend of the man in charge of the operation to help the N'Tal appeared to have committed suicide after his wife's corpse is used. His friend isn't so sure, since he had been investigating the N'Tal and thought they were conspiring right before he died. Subverted however, since there was no conspiracy, and it really was a suicide.
- Phony Newscast: This episode's teaser consists of a news report on the N'Tal's arrival on Earth and their request to take possession of the bodies of the dead.
- Puppeteer Parasite: This episode features a benevolent, mostly-benign version. The N'Tal are refugees, energy beings who need a body, and asks humanity to give them their dead. There is strain on both sides, with the aliens dying because they can't get a host in time, and some humans being Driven to Suicide by the stress of knowing that their loved ones are dead, yet also seemingly alive when inhabited by an alien. The end of this episode reveals that the children of the aliens possessing human bodies are 100% human, which makes sense, considering they don't alter the bodies' DNA.
- Was Actually Friendly: The N'Tal arrive on Earth. This time, they're openly asking to be allowed to live on Earth by possessing dead humans. Throughout the episode, several characters get increasingly paranoid about the N'Tal's agenda on Earth. It is revealed, though, that they have no evil agenda and are merely building a museum to their race, as all their children are 100% human.