Taylor, a convenience store clerk, is reading a newspaper article about the deaths of four scientists in a local particle accelerator accident when a local woman, Hannah Hutchins, comes in. Taylor glares at her and says that one of the dead men, Jack Benson, was a friend. He asks her if it Jack's death was her fault because she was the manager on duty, and refuses to let Hannah walk out. Cans suddenly start flying through the air at him and Taylor runs out... only to discover that something has switched on the gas pumps. He runs away while inside the store, Hannah crouches in a corner as the gas explodes, tearing open the front of the store.
At a hotel room, Grant is taking a shower while Melinda gets dressed in her room. He comes out and suggests that they go back to the plane separately so no one will realize that they're sleeping together, only to discover that Melinda has already left.
On the plane, Coulson briefs Skye on their new mission to confirm if Hannah is a telekinetic. He wants Skye to monitor their asset evaluation program so she can learn how they deal with someone manifesting superpowers. Skye points out that she located Mike Peterson when they couldn't, but Coulson points out that the mission didn't go well and warns that each case is different. The agent explains that Hannah was the only survivor of a particle accelerator overload and the people of Batesville blame her for the four deaths.
As they prepare for departure, Fitz-Simmons tell Coulson that the Department of Energy has sealed off the particle accelerator lab, but once on-site they can retrieve the disaster event data from the computers. As they prepare for departure, Coulson tells Skye that he'll take Grant and Melinda to confront Hannah while she stays in the car. As Grant comes in, Melinda complains that he's running late.
Once the plane touches down in Batesville, Fitz-Simmons go to the lab while the others drive to Hannah's house. A mob has gathered outside and the local law enforcement officer can't get them to leave. Coulson goes up and introduces himself to Hannah, assuring her that they're just there to talk. Someone in the mob throws a rock at Hannah, just missing, and a police car goes out of control. Coulson yanks the thrower out of the way just in time, and then tries to calm Hannah. Before he can get through to the woman, Melinda shoots her with the night-night gun and says that it's time to go.
At the lab, Fitz-Simmons send in their drones and argue about the existence of telekinesis. The conversation turns to a pranking incident in the freshman class at the SHIELD training school, and Fitz complains that they never got to play a prank on the freshmen because they graduates three years early. Jemma points out that Skye never went through training so that technically she's a freshman.
Once they have Hannah onboard in an electromagnetically-shielded cell, Melinda takes off and sets a course for The Fridge, the SHIELD facility for holding individuals with special abilities. Coulson tells the team that the next interaction with Hannah will be crucial and tells Melinda to accompany him in so that she can deal with their prisoner if she goes out of control again. They go in and Melinda admits to Hannah that she sedated her to prevent an incident. Coulson insists that it was for everyone's safety and Hannah asks if she's hurt anyone. They tell her that she didn't and Melinda asks if she was angry at the mob. Hannah says that she knows her neighbors and understands why they're angry with her.
In the lab, Fitz-Simmons monitor Hannah's brainwaves, while Skye complains that Melinda knocked Hannah out. The scientists defend Melinda's actions and Skye wonders why their teammate has the nickname "The Cavalry." Improvising, Fitz says that Melinda rescued a team of SHIELD agents from a hundred enemy agents by riding into the compound on a horse. As Skye takes that in, the scientists review the data from the incident and Fitz irritably tells Skye that she can't work the hologram device. She goes off to use her own computer and Fitz-Simmons congratulate themselves on playing the first part of their prank.
Hannah tells Coulson that as manager, she received reports about a faulty coupling assembly the accelerator. She had the part replaced and tripled-checked it, and didn't find anything wrong. However, Hannah figures that she must have missed something, causing the four deaths. Coulson assures her that his team is trying to find out the true, and suggests that she has gained a telekinetic ability. Hannah doesn't believe it and says that God has abandoned her and demons are causing the incidents around her.
The team assemble in the lab to review the data and they figure that Hannah is blaming herself out of guilt. Coulson warns the others that Hannah is a danger to them until they figure out a way to shut down her powers. As he goes to his office, Coulson is unaware of a figure lurking in the shadows behind him. Skye goes after him with Melinda and asks to talk to Hannah. She's checked the woman's history and confirmed that she's a genuinely nice person, doing volunteer work in the neighborhood. Skye dismisses Hannah's ranting about demons as hallucinations brought on by guilt, and complains that Melinda knocked the woman out. Melinda says that Skye will stay away from their prisoner. As they talk, a collectible baseball from Coulson's collection falls on the floor. He picks it up, surprised that it fell since the case was glued down, and tells Skye that for now all she can do is do a background check.
Skye goes to see Grant, who is in the galley making a meal. She complains about Melinda is so single-minded and causally suggests that the female agent needs to get laid. Grant hesitates briefly and then suggests that Skye take a less confrontational approach. They talk about Melinda's nickname and Grant realizes that Fitz-Simmons were playing a prank on Skye earlier, exaggerating Melinda's mission. He explains that she only killed twenty mercenaries, not a hundred, and that Melinda was just satisfied to get the job done. Grant reaches for a knife to cut up some vegetables and discovers that it's gone when he wasn't looking.
Hannah is cowering in the corner of her cell as someone pounds on the door. She begs God for forgiveness as the pounding continues.
Examining the hologram of the accelerator data, Jemma finds the coupling. She turns to tell Fitz and ignores him when she realizes that he's wearing a gas mask. Fitz complains about how she didn't react and goes to get some couplings they have in storage so they can simulations. As he goes, Jemma tells him to work on the prank and Fitz says that it's only a matter of timing.
Skye goes over the incident reports from the lab and discovers that one of the dead technicians, Tobias Ford, filed three safety complaints against Hannah. It was clear that he had it out for her, and she realizes that he was right.
Fitz goes to the storage room and sets the gas mask down. He notices a mop that he can use for his next prank and picks it up... unaware that a man is coming up behind him. When the scientist turns a second later, the man is gone.
Jemma is working on the hologram when she hears who she assumes is Fitz coming in behind her. She turns to tell him that the accelerator has opened a portal to another dimension, only to discover that Tobias is the one behind her. He insists that it's a portal to Hell and uses a wrench to smash the hologram projector. Coulson hears the noise and runs in, and Tobias disappears as mysteriously as he came. Jemma tells her superior that there's someone else on the plane with them.
In the electronics bay, Tobias reappears and smashes the circuitry. In the lab, Coulson realizes that the power to the engines it out and they're going down. Grant and Skye go to the cockpit and Grant helps Melinda bring the plane in for a dead stick landing while Skye looks on. In the back, Coulson and Jemma strap themselves in. The plane come down rough and taxis to a halt, and the team reassembles in the briefing room. Jemma describes Tobias to them while Melinda confirms that the power to Hannah's cell is still on full. They figure that Tobias is the one responsible for everything that has happened to Hannah and that she's not to blame. Skye wants to tell her that but before Coulson can respond, they realize that Fitz never returned.
Fitz finally gets the door to the storage closet open and discovers that someone jammed it with a knife. He figures that one of the others is paying a prank on him and goes exploring. Grant and Jemma come out, startling him, and they call Melinda. She is in one of the avionics bays and confirms that Tobias has sabotaged the power. She shuts down power to the flight controls now that they're on the ground and then goes to Hannah's cell, figuring that Tobias might head there as well.
Coulson goes to his office and tires to call SHIELD HQ on his radio. However, Tobias gets to the generator and smashes it, taking out the radio.
Skye goes to talk to Hannah through the cell door, assuring her that what's happening isn't her fault. Hannah asks her if she believes in God, and Skye says that she doesn't. However, she doesn't believe that anyone deserves punishment from God, and if God exists than God is love. Hannah admits that she wants to believe that God isn't punishing her, but finds it hard to do. Melinda arrives and tells Skye to go help Coulson repair the emergency transceiver while she stands guard. Skye tries to argue but Melinda makes it an order. Before she goes, Skye tell Melinda not to hurt their prisoner more than she already has.
As the trio go to the generators, Jemma tells Fitz and Grant that the scientists at the lab were trying to generate a portal to another dimension. Tobias became trapped between universes, able to pass from one to another, appearing and reappearing. They get to the generator room and discover that Tobias has sabotaged the equipment. Grant tells them to work while he stands watch outside. However, Tobias appears behind Fitz-Simmons and shoves them into a storage closet, and then locks the door. When Grant returns, Tobias disarms him by phasing in and out of reality, keeping one step ahead of the agent. He finally goes for Jemma, using her as a shield, and gets behind Grant to knock him out... and then stares at his hand in horror as it fades out on its own. He then shoves Jemma back in the closet and locks the door.
As Skye and Coulson work on the emergency transmitter, Skye complain about Melinda, derisively using her nickname. Coulson objects and explains that the story about Melinda has been exaggerated all the years since. He was there as part of a team sent in to find prisoners being held by a cult leader with powers. Melinda decided to fix the process and went in on her own. When she came out, she was changed. Coulson says that she used to be quiet but determined, played pranks, and broke the rules. However, after the mission, that part of Melinda was gone. Skye realizes that Coulson wanted Melinda on his team so that he could try to bring back the person that she was. As they talk, Tobias locks the office door, and then phases in and grabs Skye, and orders them to let him into Hannah's cell.
Fitz calls Melinda on the intercom and tells her what Tobias is up to, and that he's fading away every time he phases between worlds. Tobias comes up behind Melinda and tries to attack her in the flickering lights. She slips away and he soon realizes that she's taken Hannah with her off the plane. Meanwhile, Melinda leads Hannah into the nearby forest. Hannah wonders what she plans to do and Melinda says that she's going to fix the problem.
Coulson and Skye realize that they can't get past the lock door. Looking around, Skye asks Coulson if anything in his collection of antique spy equipment works.
Once Grant wakes up, the scientists tell him what happened and note that Tobias is using a wrench that phased over with him during the accident. Grant figures that it's the same wrench that Tobias used to loosen the couplings on the particle accelerator. Coulson calls them on an antique wrist radio and tells them that he and Skye are locked in. They compare notes and realize that Melinda isn't with either group.
Melinda spots a nearby barn and takes Hannah there, and says that she'll use the woman as bait to bring Tobias within striking distance. When Hannah wonders what she plans to do then, Melinda says that she'll do what she has to.
Fitz walks Coulson through attaching the wrist radio to the lock on the office door. The scientist then overloads it with a transmission signal, blowing out the lock. The team tries to work out what Tobias is doing, but Grant isn't interested and is ready to shoot the technician. Thy go to a storage room to get drones to find Tobias and Fitz is startled when the mop he rigged to scare Skye startles him. As the scientist screams, Skye realizes that Tobias is acting childish.
As Hannah waits in the barn, Tobias approaches her. Melinda ambushes him but despite her best efforts, Tobias is able to keep ahead of her by phasing in and out faster than she can strike.
Skye explains that Tobias was simply trying to get Hannah's attention so that he could be with her. They figure that Tobias was trying to protect Hannah, attacking anyone that he believed was a threat to her. As they discuss the situation, Fitz releases the drones and they home in on Tobias.
When Tobias focuses on Hannah, Melinda manages to knock him down and then tries to get the woman out. Realizing that she can't fight the man, Melinda tells Hannah to get him to help. Hannah appeals to him to stop and Tobias explains that he's been dragged to Hell for loosening the couplings on the accelerator. He didn't want to hurt anyone, and he's been trying to atone for his sin by protecting Hannah from the townspeople when they believed that she was responsible. Tobias asks Hannah to forgive him, but she says that only God can do that. Melinda agrees, telling Tobias that what he did can't be undone. She tells him to let go of the person he thought he could be because he's dragging Hannah down with him.
As one of Fitz's drones arrives, Melinda tells Tobias to let Hannah go on his own before her team arrives and makes him do it. Tobias takes Hannah's hand... and then lets himself fade back through the portal. As Skye goes to comfort Hannah, Coulson asks Melinda what she said to Tobias. Melinda tells him that she said the same thing that Coulson said to her years before: let go of the girl.
Back on the plane, Skye assures Grant that Hannah is doing better and has finally gone to sleep. She then goes to see Coulson, who says that the wrist radio is a lost cause. Skye tells him that Melinda isn't, and that if anyone can bring her back, it's Coulson. Coulson congratulates her on handling the situation, pointing out that Skye was right about Melinda, Tobias, and Hannah. He says that he wanted her to pay attention to the evaluation and intake process because one day she'll be one of the best. Skye then goes to the cockpit where Melinda is flying the plane. She asks if she can sit there and keep her company, and Melinda doesn't tell her to get out.
Later, everyone but Melinda and Fitz are playing Scrabble. Fitz comes in, complaining that someone put shaving cream on his hand while he was sleeping. He insists that the bunks should be off-limits and demands to know which one of them played the prank. All four of them deny it... while Melinda, smiling, listens in on their conversation from the cockpit.