The mysterious Lorelei and Jimmy, the newlywed man she holds spellbound, pull into a desert rest stop where a group of bikers are gathered. Lorelei is impressed by the motorcycles she sees. She tells the biker gang's leader, Rooster, that he and his men now serve her. The newlywed is forcefully cast aside by Lorelei, who asks to be introduced to all of her obedient men.
Skye is awake, conscious and desperate to get out of bed. Simmons can't allow that just yet as she continues to do relentless blood work on her patient. She's under orders to do her research in-house by Coulson, who has been taking personal time to try to contact his superiors. While he's away, the team learns that S.H.I.E.L.D. is to be the welcome wagon for a possible Asgardian arrival in the California desert. They get there just as Lady Sif arrives to declare that this world is in grave danger.
Lady Sif needs help finding Lorelei, who uses sorcery to mend and shape the will of men to serve her own purpose. She does this through the sound of her voice and her touch. There's a collar that can prevent this from happening. Lorelei wore it for centuries. Right now she's building an army. Lorelei uses her power over biker man Rooster to have him dispose of his wife inside the bar they own. When the team arrives, the local cops out front open fire. They are under Lorelei's spell, too.
Once the police are neutralized, Lady Sif enters the bar to do battle with the bikers. Lorelei sneaks outside to put Ward under her spell. The two of them drive off into the desert. Lady Sif is furious that they got away. The collar is broken. Coulson needs Fitz and Simmons to fix it so that the enchantment can be snapped. Skye is tasked with finding the fugitive couple's location, which happens to be Caesars Palace in Vegas where Ward and Lorelei get hot and heavy in a hotel room.
Ward assures Lorelei that he will eliminate her threat. He has an advantage. He knows how S.H.I.E.L.D. works. After the team searches Vegas, Fitz locks Sif in a secure room aboard the bus. He's under Lorelei's spell. Skye and Simmons are also locked up as Ward pilots the bus into the air. Coulson acts as if he's also there to serve Lorelei, who takes down May with one punch. Elsewhere, a hatch opens in the room holding Lady Sif. She grabs hold of the collar but ultimately flies out of the plane. She hangs on to the opening until she can make her way back inside to confront Lorelei.
Ward pulls a gun on May. She's a threat. Lorelei says Ward revealed who he desired before her and it wasn't May. Two battles then take place. Sif and Lorelei engage in a swordfight while Ward and May take part in some hand-to-hand combat. Coulson also knocks out Fitz for his own good. As for the other slugfests, Sif gets the upper hand on Lorelei. She straps the collar on her. This snaps Ward back to reality. May slugs him anyway just for good measure.
Lady Sif bids adieu to the team as she brings Lorelei back to Asgard. Coulson asks May to hash things out with Ward. That's not going to happen. The two of them are done. May says that if what Lorelei said was true, then Ward was more honest with her than he is with himself. Coulson tells Skye that he discovered the source of the drug that saved them both. It was alien. That's why he tried to stop them from injecting her with it. Skye doesn't care. They are both alive.
Coulson says they need to keep this information between them. They are going after the long list of questions they have about this powerful secret they share. They are going after the person responsible for this and they will make them pay. We later see that Melinda May has been listening in on their chat via a hidden microphone. She makes a call through an encrypted line to disclose that Coulson knows.