"Suits" season 5 is returning next week and viewers are eager to find out who really sold Mike (Patrick J. Adams) out.

At this point, no one has a clue as to who really turned Mike in to the authorities. In "Suits'" Facebook page, a poll was conducted for fans to vote who among the characters is the culprit.

Laura Zane (Megan Gallagher) is considered a possible whistleblower. As Rachel's (Meghan Markle) mother, she only wants the "best for her daughter" as stated in the show's Facebook page. Was she desperate enough to stop her daughter from marrying Mike that she had to turn him in?

Travis Tanner (Eric Close) is also a potential candidate, although he claims he's already a changed man. And then there's Louis Litt (Rick Hoffman), who's been a villain in the series. Did he break his promise to keep Mike's secret?

It's unlikely that Louis sold Mike out, because as already announced by showrunner Aaron Korsh, none of the six main characters is the suspect.

It appears that fans are not the only ones who are interested in Mike's issue. Even Sarah Rafferty, who plays Donna in the legal drama series, admits she's having a difficult time figuring things out.

Speaking to the Hollywood Outbreak, Rafferty admits that the finale episode of season 5A was shocking. She also said that it's hard to figure out who knows Mike's secret, apart from the six, and how come there's another person who knows about it as well.

"We can guess that some people might have a rough idea, but it's the motivation that's kind of hard for me to figure out," she explained.

Although it's easy to assume that anyone who already knew about Mike's big secret could be the whistleblower, it doesn't necessarily mean that other characters are out of the suspects list.

Korsh told the Hollywood Reporter last year that it could also be someone who recently found out and decided to report the college dropout.

The real answers will soon be revealed as "Suits" will return on Wednesday, Jan. 27, at 10 p.m. EST on USA Network.