Roswell is hosting a 3-day alien convention. The aliens are hoping to find an expert on aliens who isn't a crackpot, while Sheriff Valenti meets up with a man named Hub. Hub taunts him about the mental state of his senile father and then comments that he is finally become an alien hunter, just like Hub and James Valenti Sr.
Liz panics when the folks who witnessed the shooting and her subsequent healing experience are back and very suspicious. She tells Max, who dislikes how distracted he gets around her, and then he decides to throw himself headlong into his job to help keep his mind off Liz.
Jenny, the women from the shooting, reveals to Liz that ever since the shooting incident, her husband-to-be Larry has been obsessed with aliens. Ironically, Liz finds that she can relate to this experience of guys and their obsessions.
Valenti returns to the nursing home where his father is staying to ask him more questions about Hubble and the Silo murders. James Sr. accidentally shot a vagrant accidentally during the Silo murders, which resulted in him being committed. James Sr. says it has to do with Hubble's wife and child. Sheriff insists that Hubble never had a wife or child, and leaves discouraged.
Milton attempts to get information out of Hubble, explaining to Max that he might be the only person to have really encountered an alien. He also explains that Hubble disappeared for 30 years and is very closed mouthed about what he saw. Later, at a panel discussion, Larry reveals what happened at the Crashdown Café. As he reveals what happened in September, Michael quickly gives him a rash so that he comes across as a crazed lunatic. Accordingly, most of the people present think he's insane. Hub, however, is intrigued by Larry's story and wants to know more.
Hubble shows Valenti various pictures of dead bodies with handprints on them that presumably originate from the fourth alien. Hubble hints that Valenti knows more about this phenomenon then he lets on, and then he reveals that he knows about Max Evans. Valenti discovered that one of the pictures shows a car with a license plate that belongs to Sheila Hubble.
Hubble volunteers to give a presentation of his alien knowledge for the convention, but he has unfortunately left his slides at his hotel room and his car is in the shop. He suggests that Max could drive him over to Bitter Lake Motel, and that they could talk on the way there.
En route to Bitter Lake, Hubble recalls how his wife died (via flashbacks). In the flashbacks, we see he had planned to set off firecrackers in honor of their anniversary. He walked into the drugstore/café to get matches and when he came outside he found Sheila dead, with a silvery handprint on her and a vagrant fleeing the scene. When the vagrant returned a year later, Hubble enlisted the help of James Sr. to help catch the drifter. They confronted the vagrant at the old silo and Hubble killed him.
After hearing the story of Max Evans, Hubble becomes convinced that Max is the old alien and that he is a shape-shifter who can become anyone at will. He is about to shoot Max when Valenti appears out of nowhere and kills Hubble before he can harm Max. Valenti tells Max and Michael that they were never there and that he will cover their tracks. Max yells at Valenti for his continues scrutiny into his life and then leaves with Michael. Valenti reports the murder, alone.