At Logan International, the team moves in on John Douglas Keller, one of Moreau's men and a smuggler arriving in Boston with antiquities brought in from Baghdad. They figure that the best way to get close to him is at the airport before he gets outside and meets his bodyguards, and then make a briefcase switch. As Eliot closes in, a young girl, A'yan, asks him for help finding her family and Nate takes over. Hardison is at the customs desk and finds out that Keller is heading for London after a short stopover. The security alert goes off and the guards arrest A'yan. Meanwhile, Keller confirms with his bodyguard Ennis that the other nine refugee children he was using for smuggling made it in. Nate has Parker and Eliot tail Keller. Sophie wants to go to see the child, but Nate warns that she's under tight security and goes to talk to the girl's family.
Sophie and Nate meet with the immigration advocate, who explains that all he can do is file paperwork and it will take months to get A'yan released. They realize that Keller forces children to smuggle in statuary at gunpoint, and then sells it to buy drugs and guns. Sophie hates the idea of someone selling art for blood.
Back at base, the team tries to find a way to get at Moreau through Keller. Moreau started in the antiquity-smuggling business and has since passed it on to Keller. The pieces aren't registered or insured, so there's no way to track them. Once they're sold, Moreau uses them to fund his weapon purchases. Keller is on his way to London to sell the statuary at an auction house. Sophie is clearly disgusted that Moreau is selling artifacts for blood money. She goes down to the bar to drink, and Nate approaches her. He warns that if they get emotionally invested, they'll lose Moreau. Sophie admits that Keller steals from the rich, the same as she used to, and wonders if innocent children were ever harmed by something she unwittingly did. Nate responds by inviting her to come to London so they can steal an auction.
In London, Nate and Sophie go Claridge's Auction House, where Keller moves most of his goods. Hardison accesses the computer systems, but Sophie warns that most of the contracts will be paper files. Keller and Ennis come in, and Parker poses as a coat check girl to take his coat and his wallet. She finds a Claridge auction card and they realize it's a bid card. Keller is there to buy something, and Nate figures they need to give him one more item to move through. He has Parker put the wallet back but keep the bid card, and then sends her to the vault to find him something to use to make a connection. Meanwhile, Eliot watches Keller's car in the parking garage.
Parker gets to the vault and admires the handiwork while breaking in. Meanwhile, Sophie confirms that Keller bought a signet ring belonging to King George. She figures it isn't worth much and realizes that he wants it for himself. Parker gets into the vault and finds Napoleonic silver, Russian religious icons, and the Statue of Ra. Nate tells her to get him the Statue. Meanwhile, Sophie obsesses over the King George ring. She checks in with Hardison, who has found two files on Keller. One is about sales from the Middle East, while the other is a small file of Scottish land purchases.
Nate meets with Keller and returns his auction card, claims he moves goods, and shows off the Statue of Ra. He claims he needs to get them back to his buyer in the U.S., and wants to use Keller's connections. Meanwhile, Keller smells the Statue and realizes that it's from a local collection and not the original, and figures Nate is either a conman or a cop. Keller's bodyguard starts beating up Nate, and Sophie tells Eliot to hold back while she runs a new con. She goes in, identifies herself as the Duchess of Hanover, Charlotte Prentiss, and says that Nate is her employee, and that she needs someone to move the statue into the States and offers to double Keller's commission. When he refuses, she offers him a knighthood. When he dismisses her offer, Sophie offers him a lost barony. Nate warns her against it, but Keller takes the bait and Sophie says she can set up an interview with the Earl Marshal. She offers to meet him the next day and Keller agrees. As the team meets outside, Sophie explains that they have 200 years of worth to do.
Sophie briefs the team on how to address her as a Duchess and explains about unclaimed baronies. They realize that it's Keller's heart's desire, and his applications have been rejected six times. They're going to run the Mummy's Tiara con, which involves using a forged relic to purchase a title. They're going to need Hardison to forge the Statue of Ra, and Sophie shows him that Keller was able to determine the statue was a fake because of the odor, and it lacked the necessary spices. To fool Keller, they need to overwhelm his senses with something too real to be fake. Sophie gives Hardison a list of supplies, while Nate and Sophie go to seal the deal by having him take a secret stash of treasures back to the States.
As they go to meet Keller, Nate warns Sophie that he doesn't trust her being over-emotional, but Sophie insists that a heart con is necessary and Nate always goes with the head con. He wishes her luck and she goes to meet Keller. She offers him the private journal of a royal investor, the journal belonging to Catherine, the mythical mistress of King George the III. Sophie claims that George sent a pregnant Catherine to the States with a trunk full of treasure. She concedes the story has never been substantiated, but the man with the book can claim he's related to George.
Eliot arrives with supplies for Hardison and discovers he's wetting 1700s paper in the traditional manner, and quickly leaves.
Sophie tells Keller that the diary is up for bid at Claridge's, and she offers him the diary and a letter of recommendation in return for his helping her move her artifacts. He agrees on one condition, and brings in the Countess of Kensington to confirm Sophie's credentials. Nate tells her it's okay to leave, but Sophie stays and the Countess identifies her by her cover identity.
Parker and Eliot return to the apartment and discover Hardison printing out the pages one at a time, proud of how he's mastered the art of antique printing and fused it with computer technology.
Sophie and the Countess chat, and Keller leaves to take a call from Moreau. The Countess then asks where Sophie has been all these years, and assures Sophie that her husband William never blamed her for running off, but he died of a broken heart. Keller returns and tells them that his employer has noticed a recent incident in Boston, and wants to run the shipment immediately instead of waiting a week.
Back at the auction house, Nate hesitantly asks Sophie how real her Duchess persona is. She dodges the question by asking him how they are on taking down Keller. He calls Hardison, who is still working on the forgery. He warns them that it'll be a rush job and it will only pass the first inspection. Eliot is meeting with Ennis and his transport men and says he's under orders to inspect their facility. They inform him they are under orders to go directly to Sophie's secret stash, and Nate tells Eliot to stall by taking them on a city tour.
Keller arrives and meets with Sophie, while Nate finds Parker. She explains that she's chloroformed the auctioneer and prepares to take over for him.
Eliot drags out driving Ennis and the others around the city.
Parker begins the auction in her own unique Meanwhile, Hardison finally arrives with the fake diary and Nate picks it up from him. However, Hardison warns him that the bid has to be at least £250,000 so he can track Keller's money back to Moreau. Hardison brings in the diaries and the auction begins. Sophie uses her charms to convince Keller to bid, while Nate convinces another bidder to bid high so he can impress Parker and get a date with her. However, the man bids too high and Nate tries to have him keep it down, while Sophie manipulates Keller into bidding £300,000.
Eliot finally takes the men to the storage facility where the treasures are.
Keller inspects the diaries and accepts them as genuine, and then transfers the money. However, Keller reveals that he talked with the Countess, who explained Sophie's royal scandal. He doesn't want to be anywhere near her, and calls his man Ennis to tell him to clear it out and dispose of Eliot. Ennis draws a gun and tells Eliot to open the storage room, and Eliot lures him in and takes them out.
At the airport, Keller is taking the diary through customs and the inspector informs him that he's going to be detained. Keller shows him the paperwork, but the inspector explains that the case is made up of Russian icons that Parker stole from the auction house vault. Worse, the forgery is falling apart, and Keller realizes that he's been framed. As he's taken away, he's informed that Scotland Yard will be talking to him about the other antiquities he's been smuggling.
The police arrive at the storage unit and find Ennis tied up, and the unit filled with antiquities.
The refugee is released and the advocate thanks Nate and Sophie for helping them. The girl sees Eliot and runs over to thank him. Nate wonders where the antiquities in the storage unit came from, and Sophie admits it came from some of the first things she ever stole. When he notes that he knows her real name, Sophie explains that it was her stage name. Hardison confirms that he traced the money to Slap Shot Investments, a shell company run by Mark Vector, a hockey player. However, he's protected by the Feds after he testified. Nate gets an idea and they're off to steal a federal witness.