A troop of Boy Scouts listen to their scout masters tell a scary story around the camp fire. The scout masters, Justin, and Adam Cross, joke around about the story when the Cross says he hears a humming noise in the woods. As Cross goes to inspect it, Justin sees his cup floating out the corner of his eye. He jumps, the cup falls down and he hears the Cross yell in the distance. He tells the kids to run into the truck but something that looks like a lightning bolt hits the car and ejects the car battery. They go looking for the Cross and see him floating in mid-air, laid on his back, with electric bolts firing off around him. The kids run away.
On the bus, Coulson is hooked up to monitors as he jogs on a treadmill while Simmons checks his vitals. She asks why he is doing this since, looking at his chart, he’s not due for a physical for another 3 months. Coulson explains that he said he felt “rusty” to his doctor and they ordered the tests. Simmons states that he is in great shape, especially for someone his age.
Ward test out the “night night” gun and tells Fitz it’s an ounce too heavy. Skye and Fitz impersonate and mock Ward’s seriousness and manarisms. Simmons walks in and joins in on the fun. Ward comes back and Simmons advises Ward Fitz left a dummy round in the gun and that she fixed the weight. Ward tests it out by drawing the weapon dramatically and thanks her. The rest laugh after Ward leaves.
The team arrives at the campsite and Coulson states there was an electro-static anomaly. He states that this anomaly has a side effect they’ve never seen before. As Melinda checks out the truck, Skye and Ward poke the car battery that was ejected several feet away. Skye doesn’t understand why they were called until she sees Adam Cross’s body still floating in mid-air. Fitz-Simmons have no good answer to Coulson’s question of what might have been the cause. As Simmons looks closely at a wound on Cross’s forehead she sets off an electromagnetic charge between her and Cross, and Cross’s body falls to the ground.
Skye tries to dig up information on Cross but tells Coulson and Ward that she’s comes up empty. Ward sarcastically states everyone looks clean the first go-around, looking at Skye judgementally. She leaves to dig deeper Cross’s life. Coulson states that Ward is being pretty hard on Skye. Ward is still upset that Skye lied to them but Coulson hints that he needs to ease up.
Simmons is exams Cross’s body while Fitz, afraid, works outside the lab. She states to Coulson that his brain, as Coulson puts it, looks like a burnt baked potato because it was hit with over 2,000 megajules electro-static energy, almost double the power of a lightning bolt. Fitz states that another anomaly is occurring about 20 kilometers away.
The electromagnetic signal Fitz-Simmons are tracking increases then stops as Melinda, Coulson and Ward approach the location. They arrive at the location, a barn, and find a man dead floating 15 feet above the ground. Ward scans the perimeter for anyone not finding anything, and the scene suggests he was trying to fight something off. Skye sends over a picture of the land owner, Frank Whalen, along with first victim Adam Cross, at the firehouse they volunteer at. She also uncovers that they were both first responders during the Battle of New York.
We see another volunteer firefighter dusting off a Chitauri helmet.
Fitz sends one of his flying scanners to look at Whalen’s body, causing an electromagnetic surge like Simmons did with Cross’s body, and Whalen’s body falls into a waiting coffin. Skye advises Coulson, with Melinda and Ward headed to the firehouse, that about a dozen volunteers were first responders in New York.
They arrive at the firehouse and explain they need to look around.
Simmons examines Whalen’s body and realizes that the scare on the forehead is an exit-wound, not an entry-wound, dispelling the idea of murder.
Coulson explains to the firefighters that their friend Whalen is dead, the same way that Cross died. Tony Diaz, the man who was cleaning the Chitauri helmet earlier, dripping in sweat, asks how they died. Coulson asks if he’s OK and Diaz says no, and leaves. Coulson follows him, radioing to Melinda and Ward to shut the firehouse down, no one leaving or coming in.
Back at the lab Fitz-Simmons try to figure out what is causing this and Skye notices readings that another anomaly is happening…this time at the firehouse.
Coulson walk in the kitchen to Diaz, and Diaz asks Coulson if he can hear that humming noise. A pan starts floating and Coulson quickly draws his gun. Melinda finds the helmet and sends video over to Fitz-Simmons. Diaz advises Coulson that he cleaned the helmet with Whalen and Cross, with everyone hearing their conversation, Simmons quickly realizes that the helmet isn’t a weapon, it infected the three men. Coulson evacuates his Melinda and Ward, and the firefighters, staying with Diaz.
Coulson sits with Diaz and advises him that he doesn’t need to be afraid, and that he died. “They told me it was for 8 seconds but I know it was more”, Coulson tells him, while Melinda listens in on her radio. Coulson says he’s been to the other side and that it is beautiful. Knowing that he’s going to die, Diaz tells Coulson to leave. He leaves and standing outside, they see a flash of light indicating Diaz is dead.
Fitz scans Melinda, Ward and Coulson to see if they’re infected. S.H.I.E.L.D. agents in hazmat suits scour the area. Coulson advises they are going to the “Sandbox”, a place S.H.I.E.L.D. uses for hazardous materials, and will dispose of the helmet there. Coulson orders Simmons to find a cure, assuming more of the firefighters may be infected.
On the bus on the way to the “Sandbox” Melinda asks Coulson about his physical. He says he’s fine, now stating that his physical therapist ordered it, a different answer than the one he gave Simmons.
Simmons explains to Coulson that she’s figured out that the virus is transferred from electric shock from one person to the other. As she goes on, a metal device behind Simmons starts floating. Coulson realizes she’s infected, telling her he’s sorry and quarantining alone in the lab.
Sitting with their backs together, Simmons on one side glass and Fitz on the other. Coulson advises the rest of the team that she has only about two hours before she causes an electromagnetic charge that will rip the plane apart, and three hours before they can even land. Coulson is convinced that Simmons will find an answer.
Fitz-Simmons work on a vaccine, or anti-serum, and Fitz has built a contraption but when Simmons attempts to cure an infected mouse, it simply kills the mouse. Ward watches on the monitor and Skye walks in. He admits to her that he wishes the cause could have been a person, someone he could go after, stating that he can’t protect them, Fitz-Simmons and Skye, from something he can’t even see.
Coulson speaks with Agent Blake at S.H.I.E.L.D. HQ and Blake states they’ve never seen anything like it, and to bring it to the “Sandbox”. He also advises Coulson that if he has “infected cargo” that he needs to dump it. Coulson mocks a bad signal and hangs up on Agent Blake. Melinda walks in and Coulson says, “Don’t even think it” and she replies, “I don’t have to. That’s your job”.
Fitz-Simmons start to bicker about taking on the job culminating in Fitz realizing he may lose Simmons. They figure out if they take out cells from the helmet, they could create an antidote. Fitz runs and grabs the helmet, much to Coulson’s dismay, and brings it to the lab. He tells Simmons that they can fix this together.
They start creating an antidote as the rest of the team looks on and attach it to Fitz’ device. He zaps the third infected rat and it seems to work, but only for a moment and it meets its demise like the others. Simmons asks Coulson to tell her Mom want happens to her, and ask the whole team a moment alone with Fitz. They walk off, and as Fitz continues working, she hits him in the head with a fire extinguisher knocking him to the ground.
Coulson gets a call from Agent Blake but Coulson tells the team that the orders are unchanged. An alarm goes off and they realize it’s the cargo hold’s door opening. Ward rushes out.
Fitz is slow to get up but notices that the third rat is still alive. He screams to Simmons but she has locked him in the lab and lets herself be whooshed out the open door.
Fitz reloads his device with the anti-serum and grabs a parachute to go after her. Ward grabs the parachute from him and the device jumping out the cargo door. He catches up to Simmons, gives her the anti-serum and opens his parachute saving them both.
Back on the bus, Coulson chews out Simmons and Ward for what they did, even though he’s glad they’re alive.
Leaving Coulson’s office, Simmons admits that she never fixed the “night night” gun and it was still an ounce off. Ward says he knows, that pretends to be her mocking him. Skye rushes over to Simmons and hugs her.
Melinda goes to Coulson’s office and she sees him looking at his medical file. Coulson admits the doctors didn’t order a physical for him, he did it himself. He admits that even though the tests are fine, he doesn’t feel fine just different. Melinda asks Coulson to unbutton his shirt. She looks at the scar from Loki’s blade and states that whether he died for 8 seconds or 40 seconds, it will change someone. “You feel different because you are different” she tells him.
Simmons talks to Fitz and tells him he’s the real hero for sticking with him in the lab and helping find an anti-serum.
Coulson delivers Agent Blake the helmet. Blake warns Coulson that if he disobeys a direct order from HQ they may just take his team away from him. Coulson states “I’d like to see them try”. Blake admits he doesn’t sound like the Coulson he knew before and Coulson replies, “Get used to it”.