What started off as a seriously sexy season has now turned into a terrifyingly dark one. And it looks like the dread, woven throughout the plot of Season 3 of “Mistresses,” will only intensify during episode 10 of the hit ABC drama.

A sneak-peek video for Thursday’s installment, titled “What Could Have Been,” unveiled just how far up the river Joss (Jes Macallan) has traveled. (Hint: it’s pretty far.) During a one-on-one with her handsome lawyer David (Corey Sevier), Joss (who is currently sporting a prison jumpsuit after being arrested for murder) learned just how guilty she looks in eyes of the court when it comes to the case of Luca’s (Noam Jenkins) gruesome death.

“How the hell am I even in here?” Joss questions her attorney. “You said they didn’t have a motive.”

But David explains that the police found a motive after Calista (Jennifer Esposito) fed them “incriminating details” to make Joss look like a cold-blooded killer.

In episode 9, Calista ran to the police station (after her altercation with Joss) to tell them a new and improved story about her relationship with Joss. According to the fashion designer, Joss is obsessed with her – so much that Joss even threatened to kill Luca after she saw him flirting with another woman.

“And now he’s dead. So, you tell me,” she pressed.

Officials took her salacious statement to heart. Thus leading to Joss’ current grim situation of sharing a cell with an inmate named Roz (Katie Messina).

David explained to Joss that her case is similar to the plot of the 1992 thriller “Basic Instinct” – you know, the story of a beautiful but manipulative woman who is suspected of killing an iconic figure. But the twist in Joss’ story is that police think Joss killed Luca because she’s obsessed and in love with Calista. And apparently, there was a witness to corroborate that wild theory.

“Your ex-girlfriend Alex,” David reveals who bolstered Calista's tale. But Joss is in shock. Alex loved her. She would never throw her under the bus like this, right?

“I’m confident that she didn’t mean to hurt you,” David reveals. But the fact is, Alex inadvertently verified Calista’s twisted version of Joss by saying she too had a “fast, intense and impulsive” relationship with Joss.

“This is insane. You realize this right?” Joss cries. But David says that the police gleefully latched onto the most sensational story they could to build a compelling case for this high profile murder.

And if Joss thought she could get police to connect Luca’s death to the murder to Calista’s first husband (Joss thinks Calista killed him) – she better think again. David reveals that the demise of Calista’ first spouse was ruled out as a suicide... just like Calista originally claimed.

“This is only just the beginning, OK? Ill get you out of here,” he promises.

Click HERE to watch the sneak peek video on TVLine.

Do you think David will help clear Joss’ named? Sound off in the comments section below and don’t forget to tune into episode 10 of “Mistresses” on Thursday, Aug. 13, at 9 p.m. EDT on ABC.