Jimmy MacGregor drives Lorelei to a biker bar in the middle of the desert and stops to get something. When he goes inside, the leader of the bikers, Rooster, approaches Lorelei and compliments her. She admires his motorcycle and asks if he's the leader of the bikers. When Rooster confirms that he is, Lorelei uses her magic on him and sways him to her side. Jimmy comes out and is disappointed that Lorelei has turned her affections to someone else. When he reminds her that she said they'd be together until the end, Lorelei tells him that it's the end and hits him, knocking him across the parking lot.
At the plane, Skye tries to get out of bed and Jemma orders her to stop. Skye collapses back onto the bed, still weak from her injury, and Jemma takes more of her blood. Ward comes in and tells Skye that thanks to her, they know that Mike Peterson survived the explosion on the bridge and Garrett is trying to find him. Skye is worried about Mike, her former friend, but Ward points out that Mike left her to die at the manor in Italy. When Ward tells her to take it easy, Skye insists that she start training with him as soon as possible so that she can defend herself against any future attacks.
As Jemma analyzes Skye's blood, she admits to Fitz that she hasn't found anything unusual yet. They used all of the GH-325 drug from the vial and the only source they now have of it is in Skye's blood. Jemma complains that Coulson won't let her upload the blood test results to SHIELD. She asks Fitz what Coulson saw in the bunker when they were both there, but Fitz will only say that it was very odd.
Coulson calls in a favor with his friend, Agent Sitwell, and meets with him in a parking garage. Sitwell figures that Coulson is trying to track down Director Fury because Coulson has been making other calls, and warns his friend that no one knows where Fury is. As Coulson prepares to leave, Sitwell asks him how Tahiti was, and Coulson says that it sucked.
SHIELD contacts Melinda with new orders and she briefs the team. Energy outbursts have been detected in the California desert. As Fitzsimmons examines the readings, Ward asks Melinda where Coulson is, and she simply says that Coulson is taking some personal time. Jemma confirms that the readings are related to those seen during the arrival of Asgardian "gods," and SHIELD wants the team to meet whoever arrived.
The team take a squad of SHIELD agents to the desert, following the energy readings. As they drive, Ward asks Melinda if Coulson told her why he changed his mind about giving Skye the GH-325, but she doesn't answer. A light burst slams down in the road and a warrior woman appears. Fitz checks the records and confirms that she is Sif, one of Thor's teammates. Sif steps forward and tells them that Earth is in great danger.
Back at the plane, Coulson returns and tells his teammates that he met Sif in New Mexico when she battled the Destroyer. Melinda tells him that Sif wants their help finding someone, and asks Coulson privately if there's anything that he needs given how distracted he's been. He says that he's fine and they meet with Sif, who is surprised to see Coulson since Thor told her that the agent was dead. Coulson vaguely says that SHIELD used their own magic and asks her not to tell Thor so that he can do it himself. Sif explains that Odin sent her to Earth to find another Asgardian, Lorelei, and bring her back. Lorelei has the power of sorcery and can control men's minds with her voice and her touch. Once she controls men, she creates armies of loyal servants and conquers worlds. Sif has an Asgardian collar that will silence Lorelei if she can put it on her. Coulson suggests that they start checking the criminal records of towns in the vicinity since Lorelei will have her new soldiers bring her riches.
Rooster sends his men to steal as much money as they can. They bring it back and he shows it to Lorelei, who has no idea what paper currency is and demands gold. Rooster's wife Rosie comes in and is furious that Lorelei is wearing her clothing. Lorelei commands Rooster to choke Rosie and he does so.
Coulson brings up the computer system for Sif. As they go through the police reports, he asks her if she knows of any alien races with blue skin. Sif has heard or met of many but assures Coulson that none of them have been to Earth. They find reports about bikers robbing jewelry stores and Coulson figures that Lorelei is responsible. Meanwhile, Fitz shows Ward his modified night-night guns, which he calls ICERs, and assures the field agent that they have triple the stopping power of the original gun.
Coulson leads the SHIELD assault team to the bar and find local state troopers waiting for them. However, Lorelei has already controlled them and they open fire. Rooster looks outside and tells Lorelei that there's a woman wearing medieval carb fighting with a sword. The Asgardian realizes that Sif has come to get her.
Coulson has Sif kick a trailer in the way, providing them with enough cover to tranq the troopers. Sif breaks in through the front and Lorelei reminds her that she's beaten her before. She has the bikers attack Sif and one of them fires a shotgun blast, destroying the collar on Sif's belt. Sif knocks the bikers out and Lorelei slips out the back with Rooster. Rooster finds Ward waiting for him and the agent quickly knocks out the biker. Lorelei tries to use her voice on Ward, who resists. However, when she touches him, Ward falls under her influence. She tells him to take her to somewhere that deserves a queen.
When the team returns to the plane, Sif is furious that they lost Lorelei. Coulson tells Fitz to try and repair the collar, and then asks Skye to check Ward's drop boxes throughout the world, figuring that he'll go for one of them. Jemma gets Coulson alone and asks him to send some of Skye's blood to SHIELD HQ. When he refuses, Jemma loses her temper and insists that her duty as a scientist requires her to pursue the drug's curative powers. Coulson still refuses, telling her that he's not going to release any information until he talks with Fury.
Ward takes Lorelei to Caesars Palace in Las Vegas and Lorelei says that she can tell that he has the soul of a berserker. The agent says that he used to have feelings for one of his teammates, but it was foolish and now he'd do anything for Lorelei. They check into a hotel room and have sex, and afterward Lorelei explains that she was imprisoned in Asgard for the last 600 years. Ward promises that he won't let her get back and suggests that they eliminate the threat. Lorelei warns that Sif won't stop and Ward says that he can eliminate the people that are working with Sif.
Sif is sharpening her two-bladed sword when Melinda comes in. The SHIELD agent tries the blade but Sif warns her that Lorelei is a skilled fighter. When Sif says that Lorelei always chooses the strongest warrior she can find, Melinda warns the Asgardian that Ward is one of their best agents. Sif warns Melinda that Ward won't stop while he's under Lorelei's influence, and that she had to kill her mate when Lorelei turned him against her. When Sif says that Ward will kill Melinda if he can, Melinda assures her that Ward won't. Coulson comes in and tells them that they've picked Lorelei up on security cameras in Las Vegas.
Sif and Melinda take a team of female agents to Ward's hotel room only to discover that he and Lorelei have already gone. As Melinda searches the place, Coulson asks her if she's going to have any problems fighting Ward if it comes to that. Melinda doesn't bother to answer him and tells Fitz to continue checking the CCTVs.
The team return to the plane and Fitz admits that he's had no luck spotting Ward, figuring the agent knows how to avoid surveillance. He then leads Sif to the holding cell to show her the repaired collar. She's impressed that he's fixed it, and Fitz slams and locks the door, trapping her in the cell. Coulson and Melinda are discussing what Ward would do next and hear Sif trying to break free. Melinda realizes that Ward would come after them just as Ward lifts off in the plane. Meanwhile, Jemma discovers that Fitz has locked her and Fitz in the med pod.
Coulson finds Fitz outside the cell door and Fitz tells him that he's keeping Lorelei safe by guarding Sif. The senior agent pretends to be under Lorelei's side as well, convincing Fitz.
Melinda heads for the cockpit and finds Lorelei waiting for her in the lounge. When Melinda tries to pass, Lorelei slaps her aide.
In the cockpit, Ward opens the exterior hatch on the cell. Sif manages to grab the collar before she's swept out into the sky. Fitz arrives and relays Lorelei's order for Ward to get Sif's sword. When Ward enters the lounge, Melinda tries to get through to him without success. Lorelei tells Melinda that Ward is hers now and repeats what Ward said earlier about loving one of his teammates... but it wasn't Melinda. She then tells Ward to dispose of Melinda and leaves.
Coulson frees Jemma, who attacks him until he convinces her that he's not under Lorelei's influence. They've been monitoring the interrogation cell and tell Coulson what happened to Sif. He tells them that Sif as an Asgardian can survive and has Skye let the Asgardian back in, and tells Jemma to come with him.
On the top of the plane, Sif holds onto the collar and crawls inch by inch along the hull.
Lorelei goes to get Sif's blade, but Sif come in behind her, locking them both in. While Fitz tries to override the controls, Sif repeats her orders that she is to take Lorelei back to Asgard. Lorelei, unimpressed, tells Sif that she'll never get Thor, the man she wants, and swings at her rival with the blade. Sif grabs it and splits it in half, and the two women fight with the two halves of the blade.
Jemma comes running up and lures Fitz into chasing her into the cargo bay. Coulson is waiting and knocks Fitz out.
Melinda attacks Ward.
Sif finally defeats Lorelei and holds her blade to the woman's neck.
The two agents struggle for the gun and Ward manages to grab it and aim at Melinda.
Lorelei tells Sif that she'd rather die than go back to prison and asks the warrior to kill her. When Sif refuses, Lorelei reminds he that she used her powers and forced Sif to kill her beloved. Despite the provocation, Sif puts the collar on Lorelei and activates it.
Ward fires the gun only to discover that Melinda removed the clip when they were struggling for it. A second later, Lorelei's influence fades as Sif gags her. Sif brings Lorelei in and ward says that he's okay, but Melinda punches him one more time anyway.
Once the plane is back on the ground, Sif prepares to return to Asgard with her prisoner. Coulson says that it must have been hard for her to keep Lorelei alive, but Sif simply says that she had her orders and obeyed them. After she leaves with Lorelei, Coulson tells Melinda that she should work things out with Ward. She tells Coulson to do the same with Skye, who deserves to know what Coulson found at the Guest House. Melinda then goes to the cockpit and finds Ward waiting for her. When he says that he didn't want to hurt her, Melinda assures him that he didn't. As Ward starts to go, Melinda tells him that he was more honest with Lorelei about his feelings than with himself.
As Jemma tends to Fitz's injuries, Coulson asks to talk to Skye alone. Once Fitzsimmons leave, Coulson explains where the GH-325 came from and apologizes for risking her life with the untested drug. Skye points out that he's fine and that it worked, and that's what they have to appreciate. Coulson assures her that they're going to find answers about the drug and what happened to him, but insists that they can't put their teammates at risk by letting them know. Skye agrees to the plan and Coulson promises that they'll find the person responsible and make him or her pay. As they talk, they're unaware that Melinda is monitoring their conversation. She then makes an encrypted call and tells the person at the other end that Coulson knows.