In the aftermath of the Dark Elf invasion, the team is in England checking the debris left behind to make sure nothing alien falls into the wrong hands. Gemma gets a call from her parents but ignores it, explaining to her friends that they want explanations that she can't give them.
Skye is pestering Coulson with questions about Thor and ancient mythology and how it is actually aliens. Meanwhile, Grant picks up one item and seals it away. He tells the scientists that's what they're there for, to keep things under control.
At the Trillemarka National Park in Norway, two park rangers discover that someone has defaced a park sign with a sigil. Meanwhile, in the woods beyond, Jakob Nystrom and Petra Larsen are following directions to a ring of stones. Once they get there, Jakob goes to work with a chainsaw. The rangers hear him and check it out.
Jakob cuts open the tree and finds a metal staff inside, engraved with runes. He shows it to Petra and asks if she's ready. Bracing herself, she takes it and it glows with magical energy. Jakob tells her not to fight the feeling of rage now inside of her and she screams in anger. The rangers arrive and Petra slams one of them dozens of feet away with a single blow.
Later, the team are called to the park and Gemma nervously hesitates before climbing the tree. Grant assures her that she needs to face her fear rather than let it take over and helps her up. He talks about her research, trying to distract her, while the surviving ranger tells Coulson what happened. Meanwhile, Gemma confirms that whatever was in the tree is of alien origins. She sends the readings back to Fitz at the lab, who confirms that whatever was in the tree was Asgardian. Gemma gets an imprint of the staff and Fitz recreates it in three dimensions. Skye calls to say that the two people responsible are leading riots in the streets of Oslo, and leaving a sign burned into the concrete saying, "We are gods."
When the others return to the plane, Grant goes over the records of Jakob and Petra, leaders of a Norse paganist hate group. Fitz is only able to create a 3-D representation of one third of the staff, but it's clear that it's a piece of a larger staff. Skye suggests that they call Thor, but Coulson says that S.H.I.E.L.D. has confirmed that the Norse god is off the grid. Skye figures that the paganists knew where to look and suggests magic. Coulson says that they'll meet with Elliot Randolph, an expert on Norse mythology in Seville, Spain.
In Seville, Elliot finishes meeting with a female student as Coulson and Fitz-Simmons arrive and show him the model of the staff fragment. The professor confirms that it's a piece of the Berserker Staff, dating back to the 12th century. A powerful soldier in a berserker army wielded the Staff, destroying everything in his path. He came to Earth to fight, but fell in love with humanity. When his army returned to Asgard, he stayed behind and broke the Staff into three pieces and hid each one in a different location. Elliot reads the three verses of an ancient text, and confirms that one is about a tree. Another refers to being buried with the bones of the dead, and a third "close to God." None of that is helpful, and Elliot suggests that they check out Baffin Island off the coast of Canada where Norse artifacts have been found.
As the team takes off, Coulson checks with his agents on Baffin Island and confirms that nothing is there. Skye hasn't been able to find out about the paganist group, but has discovered that they found a promising location in Seville, where the Vikings pillaged the area on two occasions. A church is built on the ruins of an 8th century crypt, and they figure that it relates to the second verse.
Skye and Grant go into the crypt while Coulson and Fitz wait outside. Grant picks up spectrographic readings and closes in on the source, and finds Elliot in the catacombs. The professor has the staff, and Grant grabs it... and is overwhelmed with visions of a well and a boy trapped inside. His scanner device goes dead and Skye runs over to find him on the ground. He wakes up and tells Skye that Elliot has the staff.
Elliot makes his way down the street and unwittingly bumps into Jakob and Petra, who are there with their group. They approach him and Jakob shows the professor that he has another piece of the staff.
Coulson sees a car go flying and calls in the others. When the agent gets there, he finds Elliot picking up his books, and the professor admits that he screwed up.
Back on the plane, Gemma examines Grant for residual effects, and he irritably insists that they're wasting time. He finally tells them that he remembered something that he hadn't thought about for a long time, and listens in as Coulson interrogates Elliot. Elliot explains that he didn't want anyone to get hurt. He just wanted to be the first to study it and prove that the berserkers were a part of history.
Gemma shuts off the screen and tells Grant that he's growing increasingly excited. Skye asks if the memory was about his brother, but Grant snaps at her, saying that all she does is talk and talk. He gets increasingly angry and Gemma tells him that he's suffering from an adrenaline surge. She offers him a tranquilizer but Grant refuses, saying that he can't defend the team if he's sedated. Grant reminds Fitz that he had to save Gemma before and probably will have to do it again, and storms out.
Elliot insists that he wasn't involved with Jakob and Petra, and that he just wanted to uncover something belonging to the gods. Coulson explains that the Asgardians are aliens, not gods, and the professor insists that's all that he knows. The agent tells him to get comfortable and leaves.
Grant is working out with a bag while remembering the well and the boy. Melinda finally comes in and tries to calm him down, pointing out that the last thing he needs to do is punch things. Grant says that the only thing he needs to do is stop the paganists before they hurt someone else.
In an abandoned building, Jakob addresses the other paganists, saying it's time for them to get back power. He has two of his followers grab the staff pieces and they're overwhelmed by the same rage.
As Coulson watches Elliot on the monitor, Grant comes in and explains that the staff's influence has him thinking about his childhood. He admits that he felt hate and it won't go away, and tells Coulson that he can't trust himself. Coulson figures that he can trust Grant if he can tell him what he's going through. However, he doesn't trust Elliot's story and suggests that Grant let out a little rage. Grant goes into the interrogation cell and demands to know what the staff did to him. Elliot insists that he doesn't know anything else, and Grant tries to stab him with a knife. The professor casually catches it and twists the blade, and Coulson comes in and admits that he suspected that Elliot was Asgardian.
Elliot easily breaks his shackles and Coulson figures that he's the Asgardian warrior that stayed. Meanwhile, Skye, Fitz, and Gemma watch on the monitor and the scientists are eager to take a few samples. Melinda locks the cell to prevent Elliot's escape.
In the cell, Elliot is confident that they will have to open the door eventually. He admits that he didn't write his own story, but he told a French girl in 1546 about his life to impress her, and her brother published it. Elliot explains that he was a mason who signed up to fight. He hated the staff and the rage that came with it, and points out that Grant doesn't like it either. Elliot warns that the staff shines a light into the owner's dark places. Since the myth was written down, people have been searching for the staff.
Coulson asks Elliot for his help, but the Asgardian insists that he's a pacifist now. He also figures that the paganists will eventually die of old age, but Coulson warns him that he'll call in Thor if Elliot doesn't help them. Elliot finally tells them the third staff is hidden in a monastery in Ireland where monks first took him in.
The team flies to Ireland and Grant ask Elliot if the staff's effects will wear off. The Asgardian says that the rage will wear off... in a few decades. As Grant storms off, Skye asks Coulson if her SO is okay in the field. Coulson figures that Grant is okay as long as he knows about the staff's effects.
Elliot leads the team into the monastery where they have venerated Elliot as a saint. Grant tells them to get moving and Elliot leads them up to the case where the staff is hidden. Jakob steps out and stabs Elliot with the staff piece. Grant pulls it out, then screams in rage and tackles Jakob, knocking off the balcony onto the floor below. Skye runs down to help her friend and Melinda goes after him. Fitz-Simmons try to help Elliot but have no idea what to do. Coulson rips open the Asgardian's chest and says that if they can keep him alive long enough, his natural regenerative abilities should kick in.
Grant and Jakob fight and Grant is plagued by more memories of the well. Despite that, he finally knocks out Jakob.
Coulson manages to reach Elliot's heart and Fitz-Simmons walk him through holding the wound together.
As Skye tries to calm Grant down, the other paganists run in and Grant grabs his staff and Jakob's. He beats them without mercy.
Grant finally remembers what happened... his brother drowning in the well. When Grant gets a rope, his older brother arrives and tells Grant to wait. After a moment, the young Grant lowers the rope anyway.
The memories end as Grant gets control of himself... surrounded by dozens of unconscious paganists. As Skye helps him up, Petra and the last paganist comes in and Grant starts to go after her. Melinda tells him to let her help, and Skye helps him away. She picks up the staff and attacks Petra, and manages to knock her down. The three pieces of the staff come together in Melinda's hands and Petra charges at her... only to be casually knocked aside. Melinda then sets the staff down, fighting for control, and nods to Grant in satisfaction. Meanwhile, Elliot revives as his wound heals.
Later, Gemma explains what Coulson did to keep Elliot alive. Her parents call again and realizes that it's time to talk to them. Meanwhile, Grant asks Melinda if she saw anything when she held it. She says that she did and he asks how he held all three... and Melinda says that she sees the same thing every day.
Coulson examines the staff, lying on the floor. Elliot comes over and says that he recognizes the look, and wonders what Coulson wants to see. Coulson explains that he was killed and can't remember what happened afterward until he woke up a few months later. He admits that he isn't haunted by it, and Elliot asks what the problem is. As they walk out, Elliot suggests that he might start up somewhere else and Coulson suggests he check out Portland.
That night, the team get a suite of rooms for the night. Grant goes to the bar to drink and Skye tracks him down. He apologizes for losing control and Skye says that she understands. After a moment, Grant explains that he saw his brother, and Skye tells him that she's there if he wants to talk about it. Grant hesitates and then says that he's going to bed, but that maybe they can talk another time. He goes to his room and sees Melinda down the hall, going into her room and holding a bottle of alcohol. She leaves the door open and Grant goes in after her.
Sometime later, Coulson is relaxing on a beach in Tahiti. The masseuse assures him that Tahiti is a magical place... and Coulson wakes up in his bed, sweating.