Thursday, "White Collar" will return with an all-new episode featuring the return of Peter's ex-girlfriend, which stirs things up between him and his wife.

It seems like the underlying theme of the upcoming episode, "Quantico Closure," is relationships since Peter and his wife Elizabeth will celebrate the anniversary of their first meeting over dinner. However, Peter's plans for a romantic evening are interrupted when he has an awkward run-in with his hot ex-girlfriend Jill Stone, an FBI agent played by "Sons of Anarchy" actress Kim Dickens. The two dated during their Quantico days, hence the title of the episode.

According to reports, Jill is likely to seek Peter's help on an espionage case. However, with Jill back in the picture, Elizabeth becomes very uneasy and suspicious. In a preview clip, it appears that Elizabeth will take Neal's help to keep a watch on her husband and Jill. That's when she witnesses the two getting closer and engaging in more than just a work relationship.

In an exclusive interview, Tim DeKay (Special Agent Peter Burke) revealed to TV Line that "She and Peter have to go undercover, and they're working on a case together. Elizabeth just does not like that idea at all. She trusts Peter, but she's not sure if she trusts Kim's character. Elizabeth is a little too involved in the case."

Also in the upcoming episode, Rebecca appears to be at Neal's apartment and Neal shows her chapter 13 of the book. They are likely to end-up getting close while trying to find what 13 holds. In the preview clip, Rebecca and Neal are also seen kissing.

According to CaterMatt.com, the official synopsis reads: "While Neal delves further into the mystery of the Codex, Peter takes on a classified espionage case with a fellow FBI agent: his ex-girlfriend."

"White Collar" season 5, episode 7 will air Thursday, Dec. 5 on USA at 9 p.m. EST. 

Watch the preview below.