Around the world, unusual phenomena are occurring that bear resemblance to signs of the Biblical apocalypse; these include a mass death of sea life in Haiti and a devastating freeze in the Middle East, and at each of these locations, a mysterious traveler opens a sealed envelope just prior to the event taking place. The Vatican tasks Father Lucci with investigating these events, though Lucci advises that they are all either hoaxes or have scientific explanations. Concurrently to this, Abby Quinn, a pregnant woman living in California, prepares for the birth of her child. Her husband, Russell, is a defense lawyer representing Jimmy Szaragosa, a man with Down syndrome, who is on trial for murdering his incestuous parents and claiming that he did so because of God's teaching. Jimmy is convicted of the crime. For additional income, Abby and Russell rent a room to the mysterious traveler, who identifies himself as David Bannon. Soon after, Abby begins to have terrible nightmares of a man resembling David being struck down by a soldier, who then asks "would you die for him?" of her. Abby also learns of the apocalyptic signs that have occurred, and combined with her nightmares and David's suspicious behavior, she begins to worry that something terrible is taking place. She snoops through David's papers and discovers an ancient note that leads her to believe that he intends to harm her child. When Abby confronts David about this, he tells her that God's grace is empty and soon, no souls will remain to be given to newborn people. Abby panics and stabs David, only for him to shrug off the injury and claim that he "cannot die again." It becomes apparent that he is actually the Second Coming of Jesus Christ. Abby's nightmares are visions of his original crucifixion, and she is the reincarnation of Seraphia, the woman who offered Jesus water only to be turned away by Cartaphilus, who was Pilate's porter who struck Jesus. The signs of the apocalypse continue to unfold and eventually cause a giant storm. Abby connects with Avi, a rabbinical student who helps her understand the events. Father Lucci, who has come to California as part of his investigation, finds her and hears her concerns. However, while meeting with Lucci, Abby spots a ring on his finger identical to the one that Cartaphilus wore and learns that Lucci is Cartaphilus himself who was cursed to wander the Earth until Christ's return to judge humanity. He intends to allow the apocalypse to take place so that his curse will finally be broken. Abby flees from Lucci with Avi's aid, and together the two of them find a Bible to learn what will happen next. They discover that the sixth sign will be a solar eclipse that will take place the next day, meaning that the fifth sign — the tortured death of a martyr for God's cause — must take place very soon. Abby realizes that clemency has been denied to Jimmy and his execution will be the fifth sign. In a panic, she drives to the prison to stop the execution; however, Lucci has already infiltrated the prison. As Abby approaches, Lucci kills Jimmy and wounds Abby and is taken away by the guards. The eclipse begins along with a catastrophic earthquake. Despondent over her failure to save Jimmy and the rest of humanity, Abby goes into labor and is rushed through the disaster to a nearby hospital. Despite the best efforts of Russell and the doctors to help her, the child's heart stops beating as Abby gives birth, thus fulfilling the seventh and final sign, the birth of the soulless child. However, Abby has another vision of her past as Seraphia and remembers Cartaphilus' question. Finally finding true hope, Abby answers the question in the affirmative—"I will die for him"—and reaches out to her child, who revives and holds her finger. Her soul is thus transferred to the child, saving him at the cost of her own life. This act of faith ends the apocalypse. Jesus appears in the hospital and tells Russell that Abby's sacrifice has refilled the Hall of Souls, ensuring that humanity will continue to survive.
The film was released theatrically in the United States by TriStar Pictures in April 1988. It grossed $18,875,011 at the box office. It received negative reviews from critics, and holds a 15% rating on Rotten Tomatoes based on 20 reviews.