Pete and Myka go to the nearby South Dakota town to pick up their belongings, delivered from D.C., Myka's suitcase is there, but Pete's haven't arrived. He realizes that her middle initial is O and tries to figure it out.
At the warehouse, Artie is considering his memories of MacPherson when Claudia comes in, startling him. He tells her to help Leena install the motion sensors so keep the other threats from getting inside. When she suggests that Wells killing MacPherson wasn't so bad, Artie snaps at her briefly and then tells her to work with Leena to put in the motion sensors. Once she leaves, Artie gets an alert from Detroit.
In Detroit, a robber is breaking into an apartment. Suddenly some force grabs him and projects him out through the wall and across the city.
The next day at the B&B, Myka is happily dancing in her room, reunited with her fuzzy slippers and teddy bears. She admits that she feels like she's at home. Artie arrives and shows them reports of criminals turned over to the police by a mysterious vigilante. He sends them to Detroit to investigate. Outside, tells Leena to resolve things with Claudia, and quickly. Once he's gone, Leena has a brief wave of dizziness.
Pete and Myka check out the apartment in Detroit and talk to the local beat cop, Kessman. He notifies them that the residents were out of town and no one else was harmed. Pete finds three flattened buildings on the floor and they realize that whoever was shot was invulnerable to bullets. When Pete wonders why the investigators didn't find them, Kessman complains that budget cuts have undermined the police.
Artie is placing motion sensors throughout the warehouse when suddenly MacPherson appears behind him. He panics briefly aNd when he turns back, MacPherson is gone.
Leena approaches Claudia and tries to reconcile with her. Claudia does her best to ignore her.
Kessman takes Pete and Myka to the local diner where the neighborhood watch meets and the owner, Loretta, plays host. Pete stays outside to make a call and Myka goes in where she overhears a neighborhood man, Sheldon, saying criminals are parasites and cowards. Meanwhile, Pete reports to Artie what they've found, and wonders how an artifact could do different things. Artie says it's unlikely, and refuses to let Pete call upon Claudia to do the research. He then apologies and says he has to deal with an infestation problem.
Inside the diner, Pete introduces himself and they ask Loretta and Sheldon what's going on. Loretta gets her money from the safe to take to the bank, and they notice a leather pouch inside. They talk to Sheldon, who hasn't seen anything suspicious. When Kessman leaves, they figure that he might be the vigilante and making up for the budget cuts. The agents follow him and spot him running to an apartment where thieves have broken in. When they go inside, they find Kessman crouching over the unconscious thieves. Kessman explains that he got an anonymous tip. The hear gunshots outside and run to find the last thief... being held up by a man in a purple suit and a metal mask. The vigilante tosses the criminal aside and then flies off.
Pete realizes that the figure they saw is the Iron Shadow, a comic book superhero who is a non-powered vigilante. They wonder why he has superpowers and figure he has an artifact, and go back to the diner. They ask Loretta to open the safe and show what was in the pouch, and Sheldon objects. He explains that robbers broke into his apartment and took everything. Loretta calms him down and shows them the pouch. Inside is a key, and they realize it isn't an artifact. When they mention the Iron Shadow, Sheldon knows about the character from the comics.
The agents figure that anyone dressing up as the Iron Shadow would be a comic book fan, and go to the local store. Myka convinces the owner to give her a list of people who buy Iron Shadow comics. Meanwhile, Pete reads comics and tells Myka that his sister got him hooked on them after their father died. He has every issue except #46. When Pete repeats the Iron Shadow's mantra, Myka remembers that Sheldon said the same thing at the diner.
At the warehouse, Artie is working in his office and hears MacPherson's voice. He turns, startled, but there's no one there. Leena and Claudia come in and he admits that he saw MacPherson. Artie insists that he doesn't feel guilt, and suggests that MacPherson's psychic energies may have triggered an artifact that projects ghostly images. Claudia confirms that Rasputin's prayer rope is nearby.
Pete and Myka confront Sheldon and warn that people will eventually get hurt if the artifact runs out of control. He finally agrees to give them the artifact and goes into the next room, but uses it to fly out the window and escape. They run outside and spots Sheldon on the neighboring roof. Waves of gravity flow from him and he warns them to get out of the city before flying away. Myka realizes that the belt lets Sheldon alter his molecular density.
Artie puts the prayer rope in a neutralizer scrubber and sterilizes it. Once he leaves, Claudia accuses Leena of framing her and almost costing her the only family she has. Leena responds by noting that MacPherson did it deliberately to turn them against each other, and Claudia isn't the only one who almost lost her family. Leena leaves and Myka calls Claudia for advice.
In his office, Artie sees MacPherson's ghost again and vows not to let him win.
Claudia tracks down three items that alter density, but they're all in the warehouse. Pete suggests she checks belts like the one that the Iron Shadow wore. Claudia turns up a belt that belonged to comic book creator Jack Kirby that causes density alteration. She goes to check some battle suits in storage, while Pete figures that they have to get at Sheldon through his one weakness: Loretta.
Sheldon visits Loretta at the diner and insists that he only wants her to feel safe. She says that he knows how he feels. Sheldon then explains that he's the Iron Shadow. Myka and Pete arrive and Sheldon insists that he's using the power for good. The gravity forces go out of control and a shelf falls on Loretta. Sheldon flies away before the diner is destroyed.
Once the agents get Loretta to safety, they tell her what's happening. Claudia arrives and tells them that she found a battle suit that absorbs kinetic energy, and gloves that then release the energy safely. Pete is eager to put it on, until he discovers the suit causes impotence. He then turns it over to Myka.
Leena visits Artie and suggests that he's trying to come to terms with the fact that MacPherson was his friend. Peter prefers to focus on the fact that he was brought back from the dead, and so was MacPherson. As he runs off to investigate, Leena has another dizzy spell.
Claudia warns that the artifact's gravitational field will eventually destroy the city. They track the forces to the abandoned automotive plant where Sheldon used to work. He is radiating gravitational forces and blames them for driving him out of control. Myka arrives, entering the suit, and approaches Sheldon. She absorbs the gravitational energy, giving Pete the chance to remove the belt. Myka then fires the energy into the sky, dissipating it.
Loretta comes in and tells Sheldon that he's okay now that they have the belt, but they realize that the trunks are the artifact. The artifact runs out of control again, pulling in everything in range. Claudia warns that he's approaching infinite density and will pull in everything around him like a black hole. Myka goes at him again to siphon off the gravitational force. She grabs Sheldon and absorbs the energy, but is caught in a circuit. Pete pulls the trunks off him, shutting down the gravitational field just in time. Sheldon explains that he bought the trunks at a yard sale. He turns himself over to the agents, but Pete and Myka let him go. When Claudia objects, Myka points out that some people fall under the influence of artifacts and can't help themselves.
Artie goes to the stored room where he and MacPherson lived, and addresses a photo of the two of them. He admits that he misses his friend, and wonders if that's why MacPherson gave him the artifact. Artie finds a watch and a letter from MacPherson, leaving him the watch and wishing him luck. As Artie suggests they might talk from time to time, the ghost of MacPherson disappears behind him.
Claudia finds Leena and apologizes to her, admitting that MacPherson could have used her. Once she goes, Leena has another episode and calls Mrs. Frederic, warning her that something strange is happening.
As Pete and Myka put away the Charles Atlas trunks, Myka admits that she liked being a superhero. She also admits that her middle name is Ophelia, and the mocking commences. When Myka takes him home, he discovers that the others have bought him a big-screen TV as a distraction until his belongings arrive. Myka also gives him the one missing issue of Iron Shadow
he doesn't have. Artie insists that he's back on track and Claudia ignores him. And Pete admits that now the place feels more like home than his home.