Artie is going over a checklist of artifacts in the warehouse when Brother Adrian enters the warehouse using D.B. Cooper's ripcord. He casually tosses a boomerang artifacts and Artie attacks him. Several artifacts fall off the shelf, setting off the alarms, and Pete and Myka run to investigate. Meanwhile, Artie and Adrian duck the boomerang as it returns and Adrian demands that Artie use the astrolabe. Artie realizes that he can't kill him and Adrian threatens to kill his friends instead. He whispers into Artie's ear what he plans to do and then tosses him aside and walks away just as Pete and Myka arrive. When they offer to call in Dr. Vanessa, Artie refuses, saying that Adrian told him that he would punish all of them and Artie wouldn’t be able to stop them.
Back in the office, Artie alerts the Regents and asks everyone for their help. He tells them that Mrs. Frederic is on special assignment with Steve. Meanwhile, Claudia traces the bogus shipping address that Adrian used to smuggle out Alice's Mirror and confirms that it has been used twice, for deliveries going to Yuma, AZ, and Colorado Springs, CO. A third hit comes in for Menlo Park, CA, and the team recognizes all three locations. They are where Pete's ex-wife Amanda, Myka's sister Tracy, and Claudia's brother Joshua are all living. Claudia admits that her brother is working on a secret project, much to Artie's apparent surprise, and she discovers that all artifacts are accounted for. However, Artie figures that Adrian disabled the theft detection system. Pete, Myka, and Claudia head out to rescue their loved ones while Artie and Leena try to find Adrian.
In Rome, Father Domenico escorts Mrs. Frederic and Steve into the underground tunnels. He insists that the Vatican doesn't involve itself with disputes between ancient organizations and then leads them to the secret study of the Brotherhood. Once the father leaves, Mrs. Frederic gives Steve a miniature Tesla to guard her while she goes over the Vatican records. The room appears to have been abandoned suddenly.
Myka arrives in Colorado Springs and hugs Tracy, and a spark shoots up between them as Tracy's eyes glow briefly. Tracy dismisses it as static electricity from the new carpet and Myka confirms that her brother-in-law Kevin is away on business. She carefully avoids telling Tracy while she's really there and they go up to see the baby's room. There are gifts on the table and as Myka comments on how popular Tracy was in high school, Tracy's eyes glow again. Once Tracy goes to get some tea, Myka starts spraying the gifts with neutralizer fluid... and ruins the first one, a baby suit. Meanwhile, Tracy is in the kitchen making a lethal chemical cocktail of tea for Myka, her eyes glowing.
At the Marine Corps air station in Yuma, Pete explains to Amanda that they're dealing with another artifact. She admits that she's not feeling well and Pete notices that the bottle of water she's drinking is boiling. Pete notices a red leather box and Amanda thought that her husband Michael had sent it from Florence and confirms that she touched it. Pete confirms that the box was empty and assures Amanda that she'll be okay. He puts it in the neutralizer bag but nothing happens to it... and Amanda collapses.
Claudia arrives at her brother's home and gets no answer on his phone. She finds him standing at his lab, sheathed in amber.
At the warehouse, Leena returns to Artie's office and finds him loading a revolver. He tells her that it's time to stop with the games and is ready to do what it takes to stop Adrian. As he leaves, Claudia calls and tells Leena what has happened to Joshua. Leena checks the database and comes up with a list of possibilities. Claudia finds the tiny scroll responsible... inside of Joshua's fist, inside of the amber.
Tracy brings Myka her tea and finds her sister still cleaning up the baby suit. Myka claims the neutralizer fluid is an anti-fungal spray and claims the suit is covered in mold. Tracy's eyes glow again and then she gives Myka her tea. Before she can drink it, Myka's Farnsworth rings and she goes to take it. Tracy tries to make her take the tea and it spills on the carpet, burning through it. Myka realizes something is wrong but her sister doesn't seem to notice.
In the kitchen, Myka talks to Pete and they compare notes. She spots the drain cleaner on the counter that Tracy used and figures that an artifact is involved. The doctors have Amanda on antibiotics and nothing is helping. Myka notices a missing knife and cuts out, and Peter confirms that Amanda's temperature is rising rapidly. She mentions a bear that ate their food when they went camping and admits that she wasn't scared then, but she's scared now. Pete hugs her and notices that her tattoo of a cat is glowing. Amanda says that she doesn't have a tattoo and when Pete touches it, it disappears. His ex-wife immediately feels better... but the tattoo is now on Pete's hand and climbs up his arm onto his shoulder as his temperature rises.
Myka calls Artie, who suggests that the artifact is sibling-specific. He promises to check for related artifacts but cuts off when he discovers that Adrian has jammed the detection system. Pete calls and tells Artie about the cat tattoo, and Artie realizes that it belongs to the terrorist, Kotik, who assassinated Tsar Alexander II. Kotik was history's first suicide bomber and Pete wonders what they can do next. Artie spots Adrian in the shelves, abruptly tells Pete to cut it off if he has to, and goes off after Adrian.
Pete grabs a scalpel and asks Amanda to do it for him because they can't tell the doctors what is going on. However, it moves away from the scalpel as a radiation detector in the room goes off.
Claudia takes out a blowtorch and starts cutting through the amber surrounding Joshua's hand.
In Rome, Mrs. Frederick finds no indication of the Brotherhood's location, while Steve has Domenico confirm that none of the Brothers have gone in or out in a few months. They search for secret panels and Mrs. Frederick turns and discovers that Steve has disappeared. When she looks around, she discovers that Steve is trapped in a painting of the priests.
Myka finds Tracy and tries to explain that she's acting crazy. Tracy says that she trusts her and then says that she just felt the baby feel it. When Myka touches her stomach, Tracy grabs her, slams her up against the wall, and accuses her of always being the perfect one. They fight and Tracy goes for the missing knife, and Myka disarms and restrains her.
Amanda drives Pete back to the air station's bomb shelter. She warns him that his cell phone won't work inside and Pete says a final goodbye as he closes the doors after making one final joke. Amanda tells him that she never stopped loving him and then Pete seals himself inside.
Once Myka ties Tracy up, she searches for the artifact responsible for her sister's condition as Tracy taunts her. Pete calls and tells his partner about the tattoo artifact, and warns her that he doesn't see a way out this time. Myka tries to work out how the tattoo transferred to Amanda and suggests that it came from the leather on the box. They realize the box covering is made from Kotik's skin and Pete presses the box against the tattoo. Pete is unable to twist around to apply it to the tattoo and Myka tells him not to lie down and die. He gets an idea, puts the box on the floor, and then lies on top of it. The tattoo transfers back to the box just in time and Pete tells Myka that he's okay. After neutralizing the box, Pete goes outside and Amanda hugs him. After a moment she tells him to let go and Pete asks for a helicopter as they argue about whether she loves him or not.
Claudia continues heating up the amber and then pours cold water on it. It cracks open and she neutralizes the scroll. Claudia tries to cover but Joshua realizes that something happened again.
Mrs. Frederick removes the painting and Steve is released. She explains that the painting is a Rembrandt and some of his frames were taken from Tree of Life wood. They realize that Adrian trapped the Brothers in the painting and they start emerging. As each brother comes out, they attack and Steve stuns them.
Pete flies to Colorado Springs as Tracy starts becoming ill. She hasn't found anything but realizes that she hasn't checked the wrapping paper in the garbage.
Artie and Trailer find Adrian and Artie immediately shoots him in the shoulder. Adrian asks why he didn't kill him and Artie says that he isn't a murderer, but the brother won't be leaving the warehouse.
Claudia tells Joshua about Adrian and he wonders how the man could find him. He says that Artie set him up there, much to Claudia's surprise since Artie acted surprised earlier. Joshua admits that Artie was abrupt about the entire thing and it didn’t sound like him, and Claudia realizes what happened.
Myka brings the garbage back to the baby room and searches it with Pete. They find an elaborate ribbon hat with a cord, but nothing happens when they neutralize it. They realize that they have to cut the cord and when they do, sparks fly and Tracy recovers. She doesn't remember anything since she saw Myka for the first time when she arrived and Myka claims that her amnesia is a symptom of the pregnancy. Pete gets a weird vibe and goes outside to talk to Claudia when she calls, and she realizes why Pete is getting the vibe. Meanwhile, Myka tries to tell Tracy that a windstorm tore up the baby's room. Pete calls her out and Claudia tells them that Artie lied. They admit that Artie left them all hanging and Claudia tells them that the database system isn't down because she is accessing it via a remote testing system.
Artie puts Adrian in a bronzing chamber and the brother insists that Artie needs him and he's making a terrible decision. Despite his warning, Artie bronzes him. Meanwhile, Leena goes to the warehouse shelves and reactivates the security system. She gets an alert that the bronzing system is active as Trailer runs up, and they go to find Artie.
Mrs. Frederic and Steve calm down the brothers and explain about the astrolabe and how one of their own has gone rogue.
Artie finishes bronzing Adrian and gives a sigh of relief. However, Adrian appears behind him and Artie turns to discover that the bronzing chamber is empty.
The brothers insist that Adrian couldn't be responsible. As Mrs. Frederic tries to explain, Steve notices something in the painting.
Adrian tells Artie that he's a fool and Artie tries to shoot him. The bullets have no effect and Leena comes in. She has no idea what he's doing and Adrian laughs in triumph.
In Rome, Adrian emerges from the painting. He confirms that he has never been to South Dakota and Steve confirms that he's telling the truth. They realize that someone has been impersonating Adrian.
A crying Leena tells Artie that there is no one there. When Artie turns back to Adrian, he discovers that his tormenter is gone. He figures that Adrian used an artifact to disappear, but Leena says that she's been watching him for several minutes and Artie has been yelling at empty air. Mrs. Frederic calls Leena on the Farnsworth and explains what they've discovered. She figures that the astrolabe caused a psychotic break and that he has been sending the artifacts to strike at the others. Artie tries to cope with the realization of what he's been doing and realizes that he's been using Harriet Tubman's thimble to impersonate Adrian.
Mrs. Frederic tells Leena to leave the warehouse, but she turns and offers to help. He stands up and then says that the astrolabe is in the Dark Vault. He starts walk toward it and Leena realizes that he's a different person, and Artie tells her to get out of his way.
As they drive back to the warehouse, Pete suddenly gets a massive vibe. The last time he felt one that powerful was when his father died, and he tells Myka to call the warehouse.
In the warehouse, Leena's Farnsworth rings... lying next to Leena's corpse.