Sergel's Square in Stockholm, Sweden is abuzz with activity as citizens go about their daily routines. The only oddity of the day is the group of men walking through the area. They are well-dressed. Each holds metal briefcase that is handcuffed to his wrist. One more thing. All of the men wear red masks. They step onto a subway train drawing stares from all. One woman in particular locks her gaze on the men before closing her eyes and disabling all the lights. There's a struggle. When the train stops, the woman is gone and several of the red mask men are dead. One has had his hand severed off. The briefcase he carried is gone.
The woman from the train, Akela Amador, opens the briefcase she stole at a safe location. There are diamonds inside. Akela turns over the diamonds to a buyer vowing that she will find this man if the access card he gives her fails. Agent Coulson lets Skye know he needs her help to catch this thief once "the bus" lands in Sweden. The men who were killed wore identical outfits with matching red masks so the criminal wouldn't know which one was transporting the diamonds. The plan failed. An Instagram photo shows the woman who committed the theft. Coulson recognizes Akela immediately. She's a former S.H.I.E.L.D. agent. Coulson trained her.
Akela was believed to be dead after a botched mission. Coulson never believed it. He wants to hold off on contacting headquarters for the time being. He feels guilty for possibly having pushed his former charge too hard. The team travels to Zloda, Belarus to track down Akela. Simmons has always dreamed of visiting this place. Fitz, on the other hand, isn't crazy about another job in the field. Coulson assures them they won't have to leave the van. Too bad since Skye is in desperate need of a potty break. Ward instructs her to use an empty water bottle. That's not gonna work.
Skye, Fitz and Simmons realize they are being watched from the outside. CRASH! A truck rams the side of their vehicle. It's Akela. Skye tries to take advantage of her limited weapons training, but the truck smashes them again before she can use her gun. They are pushed over a ridge. No one is hurt, but Akela gets away. The team realizes their foe has a camera built into her eye. What she sees switches to backscatter when she closes her eyes. No one has technology like this. Coulson wants to bring in Akela. Melinda May has other ideas. She wants to take her out. Skye is on Coulson's side. After all, he believes in her, so he must a good judge of character.
The team realizes that Akela is being controlled by someone. Agent May confronts the target in her hotel room. Akela lets her know that her know that the people who control her built a failsafe. Either she kills May or they kill her. A mighty battle ensues between the two women. The lights go out. Coulson bursts into the room. He and Akela draw guns on each other. But Coulson's weapon isn't lethal. When Akela awakens after being knocked out, she wonders why her handler hasn't blown up the camera in her eye. Coulson explains that it's because he believes she's on her way to her next mission.
Ward wears a set of glasses mimicking the imprint that's in the eye camera. Coulson assures Akela that she's safe. He's also glad she's alive. Akela still feels guilt over the team she was with back when she didn't listen to Coulson's orders, as they all died. She explains how a mystery handler watches her every move. If she disobeys her orders, she dies via the failsafe. As for the mission, she gets messages from someone she believes to be an Englishman. The info comes in pieces.
Ward infiltrates the building where Akela is to complete her mission. Skye warns him via radio that he needs to avoid mirrors so the handler doesn't see his face. Ward is at a loss when he's ordered to seduce the man guarding the room he needs to access. He ends up knocking the guy out. Ward enters the secret room where the camera in his glasses snaps a picture of some type of equation on a blackboard. Alarms sound as Ward tries to make a quick escape. He's caught looking into a mirror. He orders Fitz and Simmons, who are operating on Akela to disable the failsafe, to cut the wires now. They do and she's safe.
CRASH! Ward barrels through a window to the outside world where Skye is waiting for him. They race to safety. Meanwhile, Coulson is hot on the trail of Akela's handler. He spots him trying to escape. The handler panics when he sees Coulson's S.H.I.E.L.D. credentials. His eye smokes and blood vessels pop. In an instant, the handler is dead. He was fitted with a failsafe, too. That means the real threat is still out there and they have the equation, possibly an alien one, from that blackboard.
Akela will receive a fair trial. Coulson will testify on her behalf. Akela asks May what happened to Coulson. He's different than when she knew him. She wonders what they did to him. Later, Akela is able to do something she hasn't been able to do in a very long time. She closes her eyes to sleep in peace.