Ed. Note: The following contains spoilers from "The Good Wife".

Alicia Florrick's sexy investigator Jason Crouse has been at the heart of "The Good Wife" drama this season. And on Sunday's episode, viewers find out Jason (Jeffrey Dean Morgan) has been investigating Alicia's (Julianna Margulies) life behind her back.

But first, the attorney, whose husband Peter is running for President, makes some ads with his campaign manager Ruth Eastman (Margo Martindale) before Jason interrupts. He's checking in to see if it's okay that he's also working for the Lockhart Agos firm. Alicia tells him that's fine and the two have a wild flirting session with a horrified Ruth looking on.

Later, Ruth asks Alicia's Chief of Staff Eli Gold (Alan Cumming), "Are they having an affair?" Eli denies it but Ruth says Alicia touched Jason's arm and "was smiling at him like a schoolgirl."

Ruth notes that Peter's fragile presidential campaign for the Democratic nomination, "wouldn't withstand the fallout" of Alicia being caught in a compromising position with Jason. An aggravated Eli then visits Alicia's apartment, where the lawyer is out—but Jason is in.

Eli quizzes him about how close he's getting to Alicia. When Jason is noncommittal, Eli snaps, "Her husband is running for President. There is a lot more attention being paid."

Jason takes off his glasses and stares down Eli, saying he should ask Alicia the questions, not him.

Later, when given the third degree by Eli, Alicia says sarcastically, "When I sleep with Jason, you'd rather I kept it private."

Well, yes ... the political spinmeister makes it clear Alicia needs to be much more discreet with Jason. Alicia says she's not sleeping with the investigator but indignantly implies it is none of Eli's business and asks him to leave.

Having overheard the conversation from another room, Jason abruptly leaves her apartment as well instead of sharing a drink. In another scene, he admits to Alicia that Eli had given him a warning and tells her he prefers an uncomplicated life.

Meanwhile, Ruth gives Eli a file on all the skeletons in Jason's closet, and tells him to share it with Alicia.

Eli personally confronts Jason with the most alarming point in the file—that Jason actually launched his own investigation of Alicia! Although Jason explains he needs to know about his employer, Eli isn't buying it, and rushes straight to the good wife to tell her Jason has looked into her past.

Alicia slams the door on Eli's face as the episode ends -- with Jason's actions still a mystery.  

But Jason isn't the only one with something up his sleeve. Eli secretly runs some focus groups to see how voters feel about Alicia. They all like her, which thrills the longtime political guru, who hopes to convince Mrs. Florrick to run for the Senate. But how that will impact Peter's presidential campaign remains to be seen.

Also, Sunday's episode marks the return of Monica Timmons, the African-American lawyer who challenged Lockhart, Agos & Lee earlier in the season when she was interviewed there, then posted undercover video she had made of the lawyers asking seemingly racist questions.

Monica was passed over for the job with two white males being hired instead, but she comes back and asks if the firm can help her with a client.

An African-American woman claims that the ChumHum search engine's maps have ruined her business because they are racist, indicating her restaurant is in a sketchy area and scaring away customers.   

With Diane Lockhart (Christina Baranski) and Cary Agos (Matt Czuchry) supporting Monica on the case, Louis Canning (Michael J. Fox) invites Alicia and her partner Lucca Quinn (Cush Jumbo) to help him defend ChumHum. At one point, Monica laughs to Cary that she hopes "Biff and Skippy are working out well for you," and Cary charges her with "reverse racism" for using country club names for his new lawyers.

After Alicia and her team decide to bury the fact that ChumHum's algorithm tagged a photo of a black woman as an "animal," Lockhart's firm uncovers the deception. The judge finds Alicia in contempt of court and fines her $5,000 for not providing the photo.

More evidence piles up when it's discovered ChumHum employees sent emails with racist jokes.

In a settlement meeting, Alicia tells Diane, Cary, and Monica that ChumHum's photo coder had been fired—but offers their client nothing because the reason her restaurant failed was that her own business practices were shoddy.

Cary asks Lucca if she wants to celebrate the end of the complicated case and go for a drink at her favorite downtown bar. Cary tells Lucca he doesn't dance but after she hits the floor on her own, he joins her.

"The Good Wife" airs Sundays on CBS.