Peter and Neal are shopping for a suit for his anniversary dinner with Elizabeth. Although it was going great, Peter's ex girlfriend Jill showed up, causing things to go downhill quickly. Elizabeth asked her to join them, and she revealed she has been looking for Peter, she needs his help on a case. While walking home Elizabeth says she was feeling insecure about Peter's ex, but he of course smoothed everything over and told her it is nothing.
Meanwhile, Neal was showing Rebecca the stolen chapter 13 of the Codex. Looking at the pages, Neal discovers that they are a puzzle, revealing a stained glass window. Rebecca is overwhelmed with the discovery and kisses Neal, only to be interrupted by Mozzie.
The next day at the office Peter finds out someone stole a car in Brooklyn by impersonating an FBI Agent, he thinks they used Segal's badge to do it. While Peter is giving the assignment to Neal and Clinton, Jill showed up and Peter kicked them out of the office. Jill is investigating a creator of a computer chip that can hack any computer system, named Mason Sadowski. She is going undercover and wants Peter to pose as her partner. Peter agrees and heads home to talk to Elizabeth. As he was going to tell her about working a case with Jill, she shows up and says they have to go to recon.
Using Peter's car as bait, Neal and Clinton ride around some neighborhoods trying to find the FBI impersonator. Finally they are approached by a man who says he is an FBI Agent. Neal and Clinton jump out of the car and arrest him, finding him with Segal's badge. The bring him back to the office to wait for Peter for questioning.
Meanwhile, Jill and Peter are waiting for Sadowski to leave his hotel room, but when he finally does, they are unable to uncover any evidence. Peter heads to the office to interrogate the man with Segals badge. The man said he didn't murder Segal, he was robbing a store while Segal was shot, and found the gun and badge in the dumpster. He says the store has him on camera to prove he didn't commit the murder.
Peter heads home and finds Elizabeth waiting for him. She asks about the case with Jill, but he says he can't tell her anything. This really upsets her because even the classified cases they talk about together. The next day while Peter is at work, Elizabeth goes to talk to Mozzie. He suggests following Jill to see if anything is going on.
Peter is working with Jill when they find out other people are also looking for Sadowski and the computer chip. Peter and Jill are forced to move fast, so they decide to bring Clinton in to follow the mercenaries following Sadowski, but decide not to tell him why. Clinton follows them to a diner. While he is there, Jill and Peter go to Sadowski's hotel room to buy the chip.
Elizabeth forces Neal to go with her to follow Jill. She is sitting watching as Peter and Jill go into the hotel, she quickly follows them inside. Meanwhile, Clinton looses track of the mercenaries, and calls Peter to warn him. Peter doesn't pick up his phone because Jill tells him they have to have radio silence. As they are walking in the hotel, Elizabeth runs into Sadowski, recognizing him from photos Peter has. She starts talking to him, but he says he have to go. She offers her phone number, and as he is taking her phone to put in the number, he slips the computer chip into it. As he is walking away, the mercenaries grab him and take him upstairs. Elizabeth and Neal follow, and Elizabeth quickly tells him the chip is in the phone. He takes it and hides the chip.
When they get up to the hotel room, Peter, Jill, and Sadowski are all held at gunpoint by the mercenaries. Elizabeth tells them she has the chip, and is able to distract them while Neal sneaks them free and Clinton arrives just in time with the backup.
Check out a clip below: