Plot summary

Miranda Hollander (Helena Mattsson) is a beautiful and smart young woman. She is a college professor and lives with her "uncle", Tom Hollander (Ben Cross) who works in a museum; he adopted her after a car crash killed her parents. Miranda can read books just by touching them, without even needing to open them. Miranda believes that she has lived with her "uncle" ever since her parents were killed in an accident while she was a baby. After her birthday, Miranda passes out and is sent to a local hospital. Tom is notified by the police. When Miranda arrives at the hospital, she silently transforms into alien form and kills several people. When Tom finally arrives at the hospital the following morning, he finds bodies everywhere. Tom locates Miranda, injects her with human hormones and begins driving her to Mexico.On the way to Mexico, Miranda wakes up, asking for the cause of her 'illness'. Tom tells Miranda that she is the result of an experiment that combined human and alien DNA, an experiment conducted with his friend Forbes McGuire (Dominic Keating) while they were both still in college. Tom has been injecting her with human hormones since her childhood to suppress her alien DNA. (Thus she never entered a cocoon stage and aged like a normal human.) Her parents never existed; they were just a fiction created by Tom to help build up Miranda's "normal life". Tom explains he and Forbes parted ways because of differences of opinion over their vision of their creation.When they arrive in Mexico, Miranda rests in a motel room while Tom spends the day searching for Forbes. After a few incidents, Tom and Miranda locate Forbes' current home. Forbes now lives with his recent experiment named Azura (Marlene Favela), another human/alien DNA hybrid who also serves as his assistant and lover-she is sterile to prevent offspring. Forbes supports his experiment by creating half-alien facsimiles of dead pets and relatives. Forbes checks Miranda's condition and finds that Miranda has reached the end of her lifespan and will die in days; her changes to alien form are her body's way of fighting back as her human form has a weaker immune system. The only way to deny death is injecting fresh human DNA into Miranda. Miranda won't allow that to happen when she realizes it will result in the sacrifice of another human being. Again, Miranda becomes unconscious. Tom goes searching for a "donor" and is mugged by a woman in the process. Azura then incapacitates the mugger and the two bring her back to Forbes' lab, where they succeed in extending Miranda's life.However, Miranda starts acting odd, joking about having sex with Azura. Tom checks her blood as she invites him to get drunk and have sex in their hotel room; he tells her to rest, believing she is delirious from the procedure. She leaves in a huff. Tom finds Forbes did a sloppy job; Miranda's hormones are unstable, causing her alien side to become increasingly dominant. Driven by her alien sex drive, Miranda manages to seduce the innkeeper, another hybrid; however she kills him mid-process upon finding he is sterile. She goes to a bar for potential mates, seeing that a female singer in a provocative red dress is garnering a lot of attention. She sneaks backstage, intimidating the singer into giving up her dress.Tom wishes to sedate Miranda, so they can fix the imbalance in her DNA; Forbes gives him a near-lethal dose to use, but warns that she's "100% pure creature". Making things worse is that Miranda is no longer sterile, thanks to the new stem cells. Investigating a church, Tom is attacked by Azura; she is angry that his arrival changed things. He manages to knock her out by dropping a large cross on her, leaving Azura to heal and regain consciousness. Forbes tracks Miranda to an abandoned warehouse, where she strips naked; Miranda reveals Forbes has wanted to have sex with her since they met. She squeezes his hand to make him drop the sedative; Forbes gives in to his lust, allowing Miranda to strip him. They copulate, much to his pleasure. Once finished, Miranda changes into alien form and sends her tongue down Forbes' throat, suffocating him. Tom finds them later, barely pitying Forbes.Tom takes Miranda back to Forbes' house, where he discovers via X-ray that a new creature is rapidly growing in her womb. Miranda weakly says her humanity is dying, and that she doesn't want to be pure alien. Unfortunately, Azura returns in alien form; Tom is forced to fight her. Just when Azura has Tom cornered, Miranda attacks her and apparently kills Azura. However, Azura rises again and fatally wounds Miranda before Tom kills Azura with a shotgun. In human form, Miranda thanks Tom for giving her life before dying.In the final scene a saddened Tom turns on all the gas burners and tanks in the house and leaves. The house explodes and Tom walks away, as the film ends.