Craig Howard and Samantha Howard are a young married couple in New York who dream of starting a family. When Samantha is diagnosed as infertile and they can’t afford the medical options that might help her conceive, a glimmer of hope arrives in the form of a new, relatively obscure fertility clinic. Spiritus Research Clinic, located in Lakeview, a small town about two hours away, offers free treatments and the couple decides to relocate so they can give their future children a chance.
At the clinic, something unsettling unfolds in the lab: a scientist secretly injects a red substance into Craig’s sperm with no warning to the couple. Despite this disturbing intrusion, the treatments proceed and Samantha becomes pregnant with twins, bringing immense relief and joy to the hopeful pair. Earlier in the story, Craig is introduced at a party to book publisher Earl Sidney, who spots Craig’s talent and suddenly offers a lucrative advance to publish his book.
As the pregnancy advances, Samantha begins to experience troubling, painful sensations described as scratches from the unborn twins. She grows increasingly suspicious of Craig’s new business associate and friend, and a sense of distance grows between them. A hooded stranger starts stalking Samantha, intensifying the sense of danger. In her corner, Samantha finds an ally in Father Carlo, the priest who becomes the one to warn her that she is at the center of a dark pact.
The couple discovers that the people behind the clinic and the publisher are connected to a secret church, “The New Light of Dawn,” a cult that worships devilry. The red liquid that was injected into the test-tube pregnancy is revealed to be the Devil’s DNA, and the cult’s plan is to kidnap the babies at birth and raise them to someday destroy humanity. In a tense confrontation, Father Carlo advises Samantha to drink poison to kill the babies, but she defies him and smashes the glass across his face. The priest—unmasked as the hooded stalker—drives away in a frenzy, crashing through one operating room after another until he bursts into Dr. Leeds’ office; gasoline spills as he proclaims, "He who walks with Satan shall burn in Hell," and sets himself ablaze.
Before the clinic is destroyed, Earl Sidney has already left with the metal container that holds the blood of Lucifer, sealing the fate of the doomed project. Dr. Leeds and the others are caught in the ensuing chaos as Samantha and Craig manage to escape.
Four years pass, and the couple celebrate the twins’ birthday at a costume party. A guest child, dressed as the Devil, teases one of the girls and, in a horrific twist, chokes on a grape, his skin rapidly rotting as he dies. The moment shatters Samantha, who stares in quiet horror at her own twins, now bearing the weight of the terrible fate that began with the red liquid and the pact she never asked to join.
