This week, "Suits" returned for the second half of its fifth season and the show wasted no time in revealing who sold out Mike (Patrick J. Adams).

After five years of pretending to be a Harvard-educated lawyer, Mike was arrested for conspiracy to commit fraud back in the season finale, and immediately fans started wondering who tipped off the police about him, as many people in the firm are already aware of his secret.

In the episode that aired last Wednesday, it was revealed that it was Louis's (Rick Hoffman) former fiancee, Sheila Sazs (Rachael Harris), who blew Mike's cover.

After learning that Anita Gibbs (Leslie Hope) got an anonymous message from a Harvard email address, Mike and Harvey (Gabriel Macht) thought that it was Gerard (Stephen Macht) who did it. But when Louis read the email, he instantly knew that it was Sheila who sent it. Sheila told Louis that she only sent the email because she thought that he would be happy that she's protecting the firm's reputation, only to find out that Louis already knew that Mike was a fraud.

After the episode aired, showrunner Aaron Korsh spoke with The Hollywood Reporter to explain how he and the writers picked Sheila to be the one to sell out Mike, saying that he wanted that person to be somebody who found out and handed him in simply because it was the right thing to do.

"She wasn't doing it out of malice or to get back at Mike or revenge," said Korsh. "It was just like, this is her job and she did it. That's why I wanted it to be Shiela."

The showrunner revealed that this is not the last that fans will see Shiela as "there's a twist at the end with finding out that maybe Sheila came forward." Korsh added that Louis will feel very bad about the whole thing and will end up doing something that will lead to more revelations and more actions in upcoming episodes.

"Suits" airs Wednesdays at 10 p.m. on USA Network.