At a gas station, a customer, Theodore Fogel, stops to get gas and warns another customer about using his cell phone. The new customer finds a small statue on his pocket as he begins to sweat, then discovers he's bleeding from heat blisters on his face. Staggering, he pulls out the gas hoses and collapses to the ground in convulsions as the blisters cover his entire body. The guy with the cell phone sees him as his blisters cause enough heat to ignite the gasoline, blowing up the pumps.
Perri and Carl arrive at the scene to find Jain already there with the info. Carl reveals that a terrorist known as the TerrorMaker, who sent wax figurines, used some means to burn his victims from the inside but he died a year ago. Back at the office, a national reporter named Howard Gorn comes in - he worked the TerrorMaker case. They ask him about the Beacon's one-year story and his suspicions that the FBI killed the wrong man. Gorn is dismissive of the claims of the TerrorMaker killing his victims with "hellfire." Carl asks him about the FBI profiler, Doug Panero, but Gorn doesn't have much to say. They go to visit Panero, but his wife doesn't let them in. After they leave, the wife throws the file away but Panero notices it and flashes back to the case and what he profiled.
Carl and Perri don't have much luck, as Gorn has all the notes for the book. Carl is suspicious of the TerrorMaker's claims of a biological agent that he used to cause the fires. They hear a noise and go to find a wax statue left for them, and a message saying, "I'm Back."
The next day they met with Vincenzo, who suggests they take it to Gorn because it's his case if they have enough evidence…which he doesn't think they do. Carl and Perri meet with the FBI who stick to the story the TerrorMaker is dead. Invoking Gorn's name, they get the FBI to reopen the case and check out the figurine. While a mysterious figure creates more figurines, Panero comes in to see the team and reveals the victim was someone who worked with biological agents. The TerrorMaker targeted anyone who worked with biological agents. Panero reveals that he's persona non grata at the FBI because of how the case went, but he wants to make sure the TerrorMaker is dealt with. After he leaves, Carl suspects that Panero is still afraid of something.
Elsewhere a woman greets a delivery boy and takes the foot to an older man. He takes out the food and finds a figurine, then he and the woman get in the pool. In mid-embrace the man's flesh starts to heat blister and the water starts to boil around him as she tries to call for help.
The reporters get word of the death and confirm the victim was a biotech CEO. Gorn gets word of the death and takes the notes and the story. Vincenzo, Carl, and Perri confront Gorn, who notes the new figurines are different from the original and denies any charges that he's writing what the FBI want him to. Panero gets word of Gorn's story that the new killer is a copycat and Carl comes to him for help. Panero's wife doesn't want him involved but Panero meets with Carl anyway and shows him his files. Panero is still obsessed with the TerrorMaker and doesn't believe the new killer is a copycat. Panero suspected the TerrorMaker stole the biological agent and Carl wonders how the new killer could have gotten the same agent. Carl still suspects some mystic "hellfire" is involved and offers to help Panero close the case once and for all.
Perri reveals that she and Carl have been ordered off the story by Management – Vincenzo will be in trouble if they go ahead with it. While Carl considers the situation, the mystery figure continues to work on figurines while collecting news articles of his crimes. That night he jimmies a car open and places a figurine inside. The FBI move in on him, with Jain and Gorn looking on, and get a picture of the man. The story breaks the next day, and the killer, Overton, is a trucker who transported the agents. The driver had all the stuff in his room to tie him to the murders, but Panero contacts Carl and tells him Overton was a wannabe. Carl concedes he's dropped the story but Panero refuses to talk to anyone else, then guilts him into taking it anyway. Perri confronts Carl, who insists on getting the story right and then takes off, leaving Perri to deal with Gorn. Gorn expresses his admiration for Perri trying to get the info out of him and warns her about Carl. Perri offers to help Gorn and he considers her offer.
Carl meets with Panero, who is convinced the TerrorMaker is still alive. Meanwhile Gorn hits on Perri that night as she works with him but she brushes him off and notices a locked drawer. After he leaves she finds a key to the drawer and finds it full of "Hellfire" files. She brings the files to Jain and reveals Gorn documented various discrepancies that disprove the FBI's biological agent theory, and Gorn bought the FBI line.
Carl finds that Gutman, the original TerrorMaker suspect, followed a certain route but Panero believes it's a dead end. Carl checks the transactions and sees they lead to a storage locker that someone has been paying to keep it open. Carl and Panero check it out and find a box of the figurines, the molds and paraffin to make them, and the biological agent.
They return to Panero's house but Carl puts everything together – Panero has a marker with ink that matches the note delivered to the Beacon. Carl accuses Panero of "bringing back" the TerrorMaker. It's clear Panero crossed the line and lost himself, taking on the TerrorMaker persona. Panero draws a gun on Kolchak but his wife intervenes and tries to bring him out of it. Panero apologizes and grabs one of the figures, setting himself on fire as Carl and Panero's wife can only look on.
After Gorn publishes another copycat story accounting for Panero's death, Perri and Jain protest but Carl goes along with Vincenzo to support Gorn's story, to protect Panero's reputation. Carl is left to consider what monster he might face if he ever tracks down his wife's killer.