Paige (Virginia Madsen) is hiding something from her boyfriend Captain Thomas Gregson (Aidan Quinn).

According to the synopsis for Season 5, episode 3 of “Elementary,” Sherlock Holmes (Jonny Lee Miller) discovers a secret about Paige when she employs him for a case she doesn’t want Gregson to know about.

The subject of the case is unclear, but given Paige’s history as a detective, it’s possible that the case she asked Sherlock to look at have something to do with a previous case she had worked on when she was still in service.

As Gregson revealed to Joan (Lucy Liu) last season, Paige was forced to leave her job as a detective after admitting that she and her colleagues had taken home a sum of money they recovered from the home of a known drug dealer 10 years ago. Paige cooperated in the investigation, and although she was never charged, she decided to resign from her post because she didn’t want the scandal to reflect poorly on Gregson.

Aside from the nature of the case, another exciting thing that fans should watch out for in the episode is whether Sherlock will disclose Paige’s secret to Gregson. Although Sherlock usually keeps the details of his client’s cases confidential, he considers Gregson family, so it won’t be a surprise if he tells Gregson what his girlfriend is doing behind his back.

Whatever the outcome of the case and no matter how it may affect Paige and Gregson’s relationship , it looks like everything will work out fine for the couple, as series creator Rob Doherty previously teased to Entertainment Weekly that the two might be tying the knot in the new installment. “There is a very strong possibility [to it],” he said.

While live-tweeting the Season 5 premiere last Sunday night, Doherty and co-producer Jeffrey Paul King  also teased that “big change [is] coming for Gregson in the 3rd episode.” Could it be his marital status? Only time will tell.

“Elementary” Season 5, episode 2, titled “Worth Several Cities,” airs on Sunday, Oct. 16, at 10 p.m. on CBS. Episode 3, titled “Render, and Then Seize Her,” airs the following week, Oct. 23, in the same timeslot.