Realizing the music box is part of the treasures Alex Hunter robbed from single ship, Neal lets Mozzie fake an FBI file so Brooks will enlist his help to investigate just that. They realize the musical code requires an expert, Akihiro, but he's found murdered later. Neal is found out having arranged the music-box being stolen and donated to a Russian action, then refuses to accept being 'benched' when the trail leads to rogue FBO agent Garrett Fowler, whom he presumes Kate's murdered. His excessive risks pay off.
Neal orchestrates an elaborate con to bring himself face to face with Kate's murderer.
- Open with Burke, Neal and Mozzie looking at the music box. They open it with Neal's key and find a second comb inside that plays a different song. Mozzie speculates the song itself could be a code. Neal wants to use the box to find Fowler but Burke says no.
On the street Neal and Mozzie discuss the fact Alex had both the music box and key at one point. They decide she must know something they don't. Neal hints that he knows where Alex is and that she has not disappeared to Italy.
Burke tells Diana he thinks Neal wants to find Fowler and get more info on Kate's death. Diana has information that Fowler accessed a checking account and might be in need of money. Burke's plan is to pretend the insurance claim related to Fowler's dead wife finally came though and stick a bunch of money into the account. Diana returns the music box to the safe.
Neal and Mozzie meet with an old friend in the fencing game. He tells them pieces of shipwrecked Spanish silver connected to Alex has begun to appear on the black market and the NYPD is suspicious. She is stealing her own stuff back. Neal tells Mozzie his plan is to "con the FBI."
Neal's plan is to forge a White Collar case file dealing with the silver and see if they can get Burke to think he discovered it himself. Neal's landlord needs him to babysit her dog for a few days. Mozzie and Neal age the fake file to make it look legit.
Burke looks over old files with Elizabeth. She spots Neal's file and Burke seems excited.
Burke comes into the office and asks Neal about stolen Spanish silver. The team reviews the file. Burke believes the NYPD has missed the fact that each time this cat burglar strikes, a piece of 17th century silver is involved. They have three potential targets for the thief courtesy of insurance records.
Diana tells Burke there was a hit on Fowler attempting to make an ATM withdrawl.
Mozzie is having trouble finding a code in the newest music box song. He knows a code maker who might be able to help them.
Diana tells Burke she found Fowler hiding under an alias. The hits on that alias include a "big one" which Burke doesn't know if Neal can handle.
Neal meets Alex and gives her a head's up just before she was going to steal from the family the feds are staking out. He says he doesn't want to turn her in and asks for info on the music box code. He offers to get the target off her back once and for all, suggesting she break into Diana's place and steal back the music box.
Neal returns to the surveillance van just after Burke tells Diana to look into Fowler's alias. He wants her to stay away from the office and work from home. Neal tries to convince her not to go home but she takes off anyway. After she leaves, Burke tells him that Fowler's alias was connected to the purchase of explosives for the bomb used to kill Kate. Burke says they are closing in on Fowler.
We flash to Alex grabbing the music box just as Diana comes home. Alex leaves via the fire escape.
Diana calls Burke to tell him the music box is gone. Burke immediately suspects Neal is behind the theft and tells him he won't get away with it.
The next day Diana shows Burke that a Russian heritage museum was anonymously given the music box and plans to display it next week before sending it back to Russia. Burke shows Neal the article and believes he is trying to draw Fowler out. Burke says he is "benching" Neal.
Mozzie goes to see the code maker at his antique store. He hands the man a recording of the song just as Neal walks in and updates him on recent developments. Mozzie and the code maker head to the back to work on the song. Neal grabs a pistol before leaving the store.
The feds plan is to stake out the heritage museum and look for Fowler. Burke tells Diana he wants Neal's ankle monitored watched closely.
Outside the museum Diana tells Burke Neal is at home.
We cut to Neal at his place. He places the gun in his pocket, grabs a forged invitation to the museum and unlocks his ankle monitor.
We see Fowler walk towards the museum. He enters and Burke goes in after him. Inside, Burke chases Fowler up the stairs. Fowler locks himself in a room and glances out the window looking for an escape.
Mozzie returns home to see Neal's ankle bracelet on the dog's neck. Mozzie calls Burke to tell him Neal is out of his bracelet and is probably armed. Burke gives Diana a head's up. While Fowler contemplates going out the window Neal arrives in the museum and gets his gun past security. Diana also enters the museum. Neal looks up and sees Fowler in the upstairs room. Diana spots Neal and informs Burke. Neal grabs onto a large banner and uses it to fly in through Fowler's window. He pulls his gun on Fowler and asks why he killed Kate.
Fowler says what happened "cost me everything." His career, his wife, etc. At this point Burke breaks into the room and Fowler says he did not kill Kate. Fowler tells Neal to go ahead and shoot him and Neal thinks about for a few moments. Burke urges Neal to drop his gun. Eventually he tosses Burke the gun and is placed in cuffs. Burke asks Fowler if he killed Kate. Fowler says "no" and Burke says he wants answers.
Back at the FBI Fowler says he got info regarding who killed his wife. He killed the person and was videoed doing the deed. He was contacted by a blackmailer who said if he could get the music box the video would disappear. Fowler said buying the explosives was Kate's idea, so they could pretend to have been killed. He doesn't know who is pulling the strings but it is someone very powerful. The bomb exploded early and Fowler isn't sure why. Fowler says Kate never called him.
A frustrated Neal stews at home.
Burke shows Fowler their shadowy picture of the guy they ran into earlier in the season. He regonizes it as a man named Larssen who was special forces. Diana comes in to report Mozzie's code maker buddy was killed in his shop.
At the shop Burke spots the word "Eureka" written on a piece of paper. Mozzie and his buddy apparently found something. The shop's surveillance tape was frozen to a shot of Neal, and Burke realizes that he is likely the next target. We see Alex arrive at Neal's apartment.
Alex and Neal have a drink. He tells her the target is off her back. Burke and Diana rush in with guns drawn only to see Alex handing Neal her phone number. She leaves and Burke tell him about the surveillance tape.
Cut to Mozzie sitting in the park. A man walks by and shoots him in the chest and takes something from inside his jacket, perhaps his wallet - or the recording from the music box? Blood stains his shirt as Mozzie slumps onto his side and his eyes close as the season ends.