- The Control Voice: When the machinations of fear collide with man's inventive genius the result can be both irreversible and terrifying.
Linden Stiles is about to be executed for eleven murders. However, he maintains his innocence, and will not give a confession to a Catholic priest, saying that God knows the truth. When the drugs have been applied, instead of dying he wakes up in another place, facing two sinister men, one bearing a syringe.
He's offered a choice: die by a lethal injection as he would have, or participate in an experiment. Stiles notes this is really not a choice at all, particularly for him, as his Catholic beliefs make him view the first choice as suicide. He accepts participation in the experiment.
It turns out this involves being spliced with alien DNA that was recovered from a crashed UFO. The physician who has to administer this, Ellen Kersaw, is reluctant at what's happening. Stiles' former commander, General Post, comes to visit him. It turns out Stiles refused to assassinate someone at Post's orders, and was discharged.
Stiles continues to say he was innocent, and claims the US Army had framed him after his discharge since he'd denounced the government and them. Kersaw slowly begins to think he may be telling the truth, since Stiles doesn't come off as a ruthless murderer. She also sympathizes with him as the DNA begins its changes.
He suffers greatly as his body changes, gaining bony claws on the bottoms of his hands, losing hair in exchange for a larger skull and an increased neurological capacity. Stiles' senses are enhanced, and he's able to eavesdrop on people outside of his closed, soundproof cell without trying.
After the transformation is complete, Stiles easily escapes with greatly increased strength and agility. Kersaw soon realized this is the result the Army wanted, as Post then sends some commandos to hunt him down. They must know the capability of the aliens whose DNA he has if there is ever a clash in the future.
Stiles evades them, resolutely refusing to kill even in self-defense. At the end, he lets himself be surrounded and the Army commandos are lining up their guns to shoot him. Just then, the aliens whose DNA he has reveal themselves, having been watching it all invisibly. They beam Stiles' safely away with them.
Kersaw realizes that, just as the Army wanted to test the aliens' capability, they were being tested themselves. The aliens intentionally left their DNA behind, to see what humanity would do with it. We have failed the test, she grimly concludes, implying the aliens will view us as hostiles in the future.
- The Control Voice: Can the true reason we so fear the unknown be that we know ourselves...too well?
- Ear Ache: Stiles and the aliens have an ability to emit a high-pitched sound is painful for humans.
- First-Name Basis: Stiles asks Kersaw what her first name is (it's Ellen), then tells her to call him Linden. She does, as a sign of her growing sympathy with him.
- Frame-Up: Stiles' claims he was framed for eleven murders by the US Army. Eventually, the people who did it admit this.
- Government Conspiracy: The US government and military framed Sgt. Linden Stiles for the murders of eleven people at an Army recruiting office after he disobeyed a direct order to assassinate an Iraqi warlord for purely political reasons and went public about the planned assassination.
- Humans Are Bastards: Kersaw thinks that the aliens concluded this as a result of their experiment and hunt of Stiles.
- Invisibility: The aliens display this ability at the end, having watched the test completely unseen.
- Karmic Twist Ending: Linden Stiles allows himself to have his DNA spliced with alien DNA found from a body at a crash site thus transforming him into a human/alien hybrid with enhanced senses. He is allowed to escape the government facility so as to be hunted down. When he's caught and about to be executed, the aliens arrive and kidnap Stiles while at the same showing signs of disappointment at the army, revealing the entire events to be a test which humanity has failed.
- Last-Minute Reprieve: A variation. In lieu of execution, Sgt. Linden Stiles is given the choice of submitting to a military experiment. However, as far as the observers of the execution and the outside world were concerned, the execution went ahead as scheduled. Stiles himself thought that it had until he woke up.
- Madness Mantra: Stiles chants "They can change my body, but they cannot touch my soul" while being slowly changed by the alien DNA which is spliced with his.
- Painful Transformation: Stiles undergoes one in the process of his DNA slowly melding with the aliens'. He first throws up continually, then loses his hair, grows claws on his hands, even his skull and brain enlarges.
- Questionable Consent: Stiles submits to the experiment, but the alternative was death. His religious beliefs also precluded the latter, as for him it would essentially be suicide, as the experimenters knew.
- Real Men Love Jesus: Stiles is a former soldier who steadfastly refused to go through with an assassination, accept death, or kill people even when they're trying to murder him. This all seems to be based on his Catholic beliefs.
- Sadistic Choice: Stiles is offered a choice by the US Army: death, or participation in a secret experiment whose details he doesn't know.
- Secret Test: In the final scene, Dr. Ellen Kersaw realizes that humanity was secretly being tested by the aliens to determine whether or not they should make contact with them. They failed.
- Suicide Is Shameful: Linden Stiles' execution is faked who's "volunteered" to undergo a secret experiment. They specifically chose him as he's a devout Catholic, so he won't refuse the offer as the alternative is death, which to him would be suicide.
- Super Senses: Stiles develops them as a result of being spliced with alien DNA. He can hear people speaking even inside a closed, soundproof cell and see them from quite a distance.
- Teleportation: The aliens have an ability to do this, beaming themselves and Stiles away at the end.
- Thou Shalt Not Kill: Stiles declines to kill the commandos sent after him even to defend his own life.
- Wham Line: "Don't you get it? They were testing us! And we failed."