Teenage comic book fan Cal Rawitz stops by the local comic book stores and notices that there's a copy of Tales of the Undead #1 in the display case. He talks to the owner, Charlie Evans, who admits that he got bought a copy of the comic at an estate sale for $25,000. The issue features the first appearance of Jay Star's comic book creation, Ferrus the Invincible, and is autographed by Star himself. Cal wants to get it but Charlie warns that it's priceless and he can't afford it. Cal signs up for a contest and goes over to admire the comic, and Ryan comes in to pick up his weekly comics. As he talks with Charlie, Cal tries to jimmy the lock on the display case. As Ryan goes, Charlie notices the theft and grabs the teenager. Cal breaks the case and grabs the comic book in his hand. The room starts to shake and Cal is transformed into... Ferrus the Invincible, an invincible armored robot. He strangles Charlie and then walks toward the door. Ryan hears the commotion and comes back to investigate, and Ferrus knocks him aside and departs.
Later, Ryan returns to the shop and examines a piece of armor that broke off of his attacker. Micki doesn't believe it was actually Ferrus, but Ryan insists it was more than just a man in a disguise. He explains that in the premiere issue, a teenager gets hold of a magic book that lets him transform into Ferrus, and the book becomes part of the armor. Micki figures that Uncle Lewis wouldn't have listed a comic book in the manifest, but she does find an entry for a magazine. The name of the buyer is Jacob Staretsky: Jay Star's birth name. Surprised, Ryan explains that Star disappeared into obscurity after he sold off the rights to Ferrus. Star's address is listed in the manifest and Ryan goes to talk to him.
At Star's home, Ryan tries to get past the man's middle-aged housekeeper, Mrs. Forbes. She refuses to let him in, figuring that he's a reporter there to interview Star about the 40th anniversary of the creation of Ferrus. Ryan says he's a fan and Jay overhears him and invites him in. The elderly comic book writer gives his autograph and shows Ryan the Comic Award for Excellence he received for creating Ferrus, and then wonders what Ryan really wants. He explains that someone killed Charlie, who Star knows, and the killer may have been an obsessed Ferrus fan. Mrs. Forbes, listening in, complains that the publishers cheated Star out of his rights and left him with nothing. Star tells her to leave and then takes one of his heart pills. Ryan claims that the real Ferrus killed Charlie. Star doesn't believe it and laughs hysterically, and then tells Ryan to go. However, once Ryan has left, Star tells Forbes that he's going out.
At the store, Star talks to Charlie's daughter Linda, who is cleaning up the store. He asks for a few minutes to sit and remember Charlie. Once she goes, he goes through the contest entry box and finds Cal's name and address. He goes there and listens as Cal tries to sell the first issue to Carmine DeMateo. Carmine refuses to believe Cal has something so valuable and hangs up. Star comes in and when Cal doubts who he is, shows him his prescription bottle of heart medicine. Cal is awestruck at meeting his idol, but refuses to give up the comic when Star asks for it. The teenager warns the writer to leave. When he doesn't, Cal uses the cursed comic to transform into Ferrus. As he advances on the old man, Star pulls out his Comic Award statue and stabs Ferrus in the chest, killing Cal.
At the store, Ryan tells Micki what happened. She wonders what is so important about the comics, and Ryan describes how they influenced his childhood. Micki agrees to read them a bit more carefully, while Ryan sees an article on Cal's murder. He recognizes Cal from the store and they go to the teenager's apartment. Searching the place, they find Carmine's name and phone number on the teenager's notepad. They go to see Carmine, who runs Peerless Comics, the company that owns the rights to Ferrus. Carmine says that he doesn't know what Cal wanted, and that his father bought the rights from Star in 1948. Star went on to lose the money in a phony land deal, and has no one to blame but himself. Carmine admits that Star tries to write a secret "final issue" where he killed off Ferrus. Peerless refuses to publish it and destroy their cash cow, but he doesn't know where the drawings went. He figures they might turn up at the upcoming auction.
Once Ryan and Micki leave, Star pays Carmine a visit. He says he wants the money that Carmine's father stole from him. When Carmine refuses, Star notices a piece of original Ferrus artwork and accuses Carmine of stealing it from him. Carmine denies the charge, saying he bought it legitimately, but Star insists it was in his basement. Carmine says Star can have it, but the old man wants his money. He uses the comic book to transform into Ferrus and advances on the publisher. Carmine runs past the mechanical figure, sets off the fire alarm, and runs to the elevator.
Micki and Ryan hear the alarm go off and return to investigate. Meanwhile, Ferrus has cornered Carmine in the elevator. The cousins quickly hide as Ferrus emerges, stepping over Carmine's broken body. The figure walks outside where the police are waiting. They open fire and seemingly "kill" Ferrus. Ryan insists that Ferrus can't be so easily killed, and the robot gets up and walks away.
The cousins return to Curious Goods and figure their best bet is to find the "secret" final issue showing how Ferrus was killed. They go to Star's house and Mrs. Forbes refuses to let Ryan in. when he yells that he saw Ferrus, Star hears him and brings him in to explain. Ryan asks him for the sketches showing how Ferrus can be killed, but Star claims he destroyed it long ago and doesn't remember what he wrote. He tells Ryan to leave, and Ryan tells Micki what happened. They decide to go to the auction house to see if they can find the drawings that Carmine mentioned earlier.
At Star's house, the writer searches through the basement for the sketches. Mrs. Forbes confronts him and contemptuously tells him that she sold his artwork off to pay for his bills, and she hasn't been staying with him all these years out of love. As she goes, Star suggests that she can stay if she wants, and casually asks who she should the artwork to. When Mrs. Forbes admits she sold it to a Ted Haley, Star uses the comic to transform into Ferrus and kill her.
At the auction house, Micki and Ryan talk to the auctioneer, Mr. Briggs. He tells them that the final issue hasn't arrived yet, and he figures that Haley is bringing it in at the last minute. The cousins get Haley's address from Briggs' Rolodex and drive to his house. Haley's car is outside and he's dead, killed by Ferrus. The missing issue is gone, but Ryan finds one of Star's heart pills and realizes that he now has the cursed comic.
Micki and Ryan drive to Star's house. Spying through the window, they see Star burning the final issue. Micki pounds on the door to attract his attention while Ryan breaks in. Star hears him and runs back to the fireplace, where Ryan is trying to pull out the pages. Star angrily tosses them into the fire, but Micki grabs the cursed comic from the end table where it's sitting. When Star advances on her with a poker, Ryan pulls the pages out of the fireplace. Micki drops the comic and Star picks it up and transforms into Ferrus. As he advances on her, Ryan sees that the comic shows Ferrus' vulnerability to the Comic Award statue. He grabs it and stabs Ferrus in the chest. Star, dying, asks Ryan how it feels to be the hero before he passes away.
Later, Micki visits a despondent Ryan in his room and asks to read more Ferrus comics. When she invites him to an upcoming art exhibit on comics, Ryan admits he's had enough for comics for a while. When he asks her to leave, Micki says she's sorry about what happened to his idol and gives him a picture of Star in his younger days. Ryan admits that he used to admire Star and offers to show some of the drawings he made by copying Star's work.