Kat (Tina Ona Paukstelis) is unwed and pregnant but refuses to get an abortion. Instead, she opts for adoption and contracts with Peter (Norman Moses) and Janine Null to give them her baby after it is born, as Janine is unable to bear children and Peter needs an heir so that he can inherit the family estate, a large tract of apple orchards in Wisconsin.
7 Months later: Very pregnant and posing as Peter's wife Janine, Kat accompanies Peter to visit his family at the estate. Having lived in the Philippines, the family is rather strange. There is Peter's mother Olive (Flora Coker), who is ailing and is confined to a wheelchair. Peter's sister Claire (Jamie Jacobs Anderson), whom Peter describes as "touched", lives as a recluse in a rundown cottage, and Peter warns Kat to steer clear of her. And there is Cupid (Mildred Nierras), their Filipino maid who seems to be the one who holds everyone and everything together. All in all, though, Olive and Cupid seem genuinely glad to have "Janine" there, and both are very anxious for the baby to arrive.
At dinner that evening, Kat drinks too much of Cupid's "homemade apple cider" and gets drunk. That night she has strange dreams about Peter feeding on some white liquid and then putting his head between her legs as though trying to listen to the baby. The next morning, while out walking on the Hull property, Peter and Kat happen upon a trespasser, who introduces himself as Dr Roger Harper (John Kishline) and who shows them a strange "cocoon" he has found. Harper has already found scores of them and can't explain what kind of animal made them, only that the bodies inside have been reduced to bones and it seems as though they've had their lives sucked out of them.
Peter is unhappy about Harper poking around on their land, but Kat invites him to dinner anyway. After dinner, Peter shows him some artwork from the Philippines, including a drawing of an aswang, a dark figure sitting on a rooftop and sticking its long skinny tongue down into the house. Upon returning home, Harper looks up a picture of an aswang, under which the caption reads "as*wong: a Filipino vampire who feeds on the unborn. The fetus will likely die, although some survive to become Aswang themselves." Harper immediately fears for Kat/Janine's baby, but he doesn't have time to warn her. He is himself attacked by an aswang.
Meanwhile, Kat and Peter have gone to bed, and Cupid is helping Olive into her nightclothes. While Kat sleeps, an aswang slides its long tongue into her bedroom and snakes around under the bedsheets until it finds the way between her legs. Kat wakes up, dislodges the tongue, and manages to trap it in the door. Peter rushes outside to find Olive hanging from the bedroom window by her aswang tongue. In order to release her, Peter has to cut off her tongue.
Sensing that she's in danger, Kat runs...straight to Claire's cottage where she finds Harper enwrapped in a cocoon. Still alive, he tries to warn her. Kat tries ripping him free from the cocoon but, before she is successful, she hears a noise. It is the real Janine, and she's armed with a chainsaw. Janine attacks Kat, but Kat manages to kill her with a blow to the head from a garden hoe.
Enter Peter, who injects Kat with a tranquilizer. Kat tries to run, but Peter retrieves the chainsaw and goes after her while screaming, "We have a contract...This is America...We have laws!" Kat gets away but stumbles onto the grave of Janine Hull. It's now apparent that "the real Janine" is actually Peter's sister Claire and that both she and Olive are aswangs.
Peter carries the bodies of Olive and Claire into the big house. While walking along the highway, Kat is "rescued" by the local sheriff who takes her straight back to the Nulls, oblivious to Kat's contention that they are trying to kill her. After the sheriff leaves, Peter takes Kat to Claire's cottage and chains her to a window. But the sheriff, doing his duty, calls for some information about Janine Hull and comes up empty, so he returns to the Hull house, where he is attacked and killed by a chicken (Peter).
Peter, Olive, and Cupid go to the cottage. Olive is dying and must feed. While they prepare Kat, however, Olive dies, so Peter decides to feed on Kat's baby himself. At that moment, however, Harper wakes up and Peter has to kill him first, giving Kat a chance to chop off her own hand with an ax and run away...straight back to the Hull house, Peter in pursuit, garden hoe in hand.
Meanwhile, Cupid has gotten religious. She falls down on her knees and starts to pray. When Peter orders her to kill Kat, she raises the ax to obey. Just at that moment, a tiny aswang tongue emerges from between Kat's legs, and Cupid lets the ax fall.
Five years later Cupid and the 5-year old aswang girl are saying their prayers together, blessing Grandma Olive, Aunt Claire, Daddy (Peter), and a number of Janine-mommies. [Original Synopsis by bj_kuehl.]