Episode 414 "Persistence of Vision"

When an inexplicable ghost-like being appears on a frame of wedding film ??th no evidence of tampering ??on, Donner and Stone conclude that they might have an "honest-to-goodness haunting on our hands." That's not the only thing byanding their attention: there's a serial killer loose in the city.

Stone takes the mysterious film to Father Thomas, the priest who presided at the wedding who is now administering to a group of homeless men. While astonished by the image, he admits that the only moans and creaking he's aware of can likely be attributed to old church's disrepair. As she leaves him Stone sees Gabe, an intense young man, staring at her before disappearing.

Replaying the film at the lab, Stone notices that amidst the crowd of well-wishers outside the church is the ghost ??is time, in the human form of Seth. Returning to the church, she asks the homeless men if they recognize the person in the photo, and she's directed to a nearby warehouse... briefly catching another glimpse of the mysterious Gabe. In the warehouse, Stone finds Seth; he stares at the ghostly image of himself in genuine amazement. With the promise of a meal, Stone lures him to the mobile lab for tests. He is evasive about an unusual brand on his shoulder as well as his past, mentioning only an estrangement from his father. Suddenly, he goes into a trance and sees another murder, along with where the body is. Although this incident casts suspicion on Seth, Stone believes the man is innocent. Later, Seth describes yet another murder, this time nearby. All the while, the equally-curious Gabe appears and vanishes.

Father Thomas identifies for Stone the brand on Seth's arm as angelic text and claims that if an angel is on Earth in human form, it is probably here to collect a soul. Believing that Seth is indeed an angel, Stone races to find him. At his makeshift warehouse home, she finds instead a cache of newspaper clippings about the serial murders. Then, Father Thomas appears and, agitated, delivers an eerie speech about the faithless, lost souls polluting the community... among whom he counts Stone. At that moment, the OSIR discovers, to her horror, that she has misjudged each of the three mysterious men ??ther Thomas, Seth and Gabe ??d must now deal with the truth and her own safety.