At a convenience store, a blonde woman attempts to purchase some supplies but is denied service by the clerk for the accident caused in her lab under her watch. He stops her before she can leave, but things fly off the shelf and hit him. He runs outside to escape her, believing she is using mind powers, only to see that all of the gas pumps are spilling gas. The woman is praying to God under the counter as the gasoline explodes outside.
On the bus, Coulson debriefs Skye on their supposed telekinetic. It is revealed that a particle accelerator exploded and killed four technicians under her watch. Coulson tells Skye to remain in the car while he, May, and Ward make contact with Hannah Hutchins. Coulson calmly talks to her but an angry mob begins accosting her. A police car is changed from park into drive and almost runs over a bystander. May then uses the night-night pistol on Hannah.
Fitz sends one of his nanodroids into the building where the particle accelerators blew. He and Simmons talk about how they missed out on freshman pranking. Since Skye is their "freshman," they decide to prank her.
Hannah awakens in the interrogation room, where May must explain the situation to her. Coulson is extremely calm to Hannah in order to keep her calm. She blames herself for all of the unnatural occurrences. Skye watches the surveillance of their detainee. She asks Fitz-Simmons the meaning of May's nickname "the Cavalry." They put their prank into motion by telling her an outrageous story. Skye starts her research after Fitz scolds her for playing with the hologram computer.
Still in the interrogation room, Hannah tells how the bolts on the accelerator were coming loose but a technician named Tobias said there was nothing wrong. Coulson informs her that they are working to discover the cause of her telekinetic abilities. She still denies it, saying that God is punishing her for her mistake. She says she is being haunted by demons. As Coulson sets the agents on the same track, a dark figure is watching... then disintegrates in a puff of smoke.
Skye appeals to Coulson in his office to talk to Hannah, saying that their detainee is a nice person. A collectible on Coulson's shelf falls off even though it was glued down. Skye complains to Grant about May and mentions Fitz-Simmons' story. Ward tells her a toned-down story about the real reason for the nickname.
Still worried, something begins banging on the walls of the interrogation room. Fitz sets up his prank to scare Skye. Skye turns up some information on Tobias Ford who filed complaints in Hannah's department. While in a closet, he gathers pranking supplies but is being watched by the shadowy man. Simmons makes a discovery in the hologram but the mysterious man smashes the hologram pad with a large pipe wrench and vanishes. When Coulson tries to comfort a terrified Simmons, the man cuts power to the plane.
May and Ward rush into the cockpit to crash land the plane. Coulson tells the agents that Hannah is not the cause. Skye requests the ability to talk to the detainee but Fitz is missing... locked in a closet. May dispatches Fitz to fix the power and Coulson uses his backup transmissions device until the ghost destroys the antenna receiver. Skye begins to comfort Hannah and let her know that she is safe. After a serious conversation, Skye tells her that God is not punishing her. May takes over for Skye who has to go help Coulson. While looking for the ghost, Fitz and Simmons are locked in the belly of the plane by the specter. Grant fights him but he rematerializes in the closet. Grant opens it to save them but he is knocked out into it and all three are locked inside.
Skye determines that the failure of the communications device is a hardware failure in reality. Coulson tells her not to call May by her nickname and tells the real story of the meaning behind it, during a welcome meeting something bad happened to May while helping in the mission. Coulson says she lost herself after the mission. She was somewhat like Skye but was changed after the mission. The ghost jams the lock, leaving Skye and Coulson trapped in the office.
May leaves the bus with Hannah right before Tobias is able to knock May out or get to Hannah.
Using some of Coulson's vintage agent gadgets they radio the others, and Ward, after regaining consciousness, realizes that the particle accelerator blast was caused by Tobias, who is still carrying the wrench he used to sabotage the coupling. Both groups of trapped agents realize May is gone. She takes Hannah to a barn to be "bait". The agents all escape to track down May. Simmons opens the closet to get the "golden retriever" but all of them are scared by Fitz's childish prank. Skye realizes Tobias is also being childish.
Tobias materializes at the barn and fights May. The agents realize that Tobias's real intent was to protect Hannah because he liked her and only caused the accident because he wanted her attention. A board falls, aimed at Hannah, but Tobias takes the hit. May tells him that he is trapped between our world and another, which he believes is "hell." Tobias reveals his intentions to Hannah, saying he was trying to atone for his sin by protecting her. May talks him into letting go because he is truly in hell if he is interfering with Hannah. He calmly lets go and vanishes in smoke and Skye comforts Hannah.
Coulson is sad to have lost one of his collectible agent gadgets. Skye says that May is not a lost cause but can be understood. Coulson encourages Skye to familiarize herself with the index of humans with powers since she sees the good in people. Skye enters the cockpit, asking May if she would like the company.
The agents play a game of Upword, when Fitz enters with whipped cream on his face. He accuses everyone of pranking him but he is unaware that the true prankster was Agent May.