Ani (Rachel McAdams) will be another step closer in uncovering the truth behind the Caspere murder case in the upcoming episode of HBO's crime drama series "True Detectives."

In "Black Maps and Motel Rooms," Cartermatt reports that the female detective will be seen dealing with the aftermath of her close escape from the drug-induced party in the previous episode. To make matters worse, she brought with her a potential witness to the case, and based on the promo, something or somebody is out to get her for it. At least, she believes that she will finally get some answers soon.

Meanwhile, Frank (Vince Vaughn) appears to be hatching something. Last episode, he was deep into the world of drug dealership. Just like Ani, he thinks he is coming closer to unlocking the puzzle of the Caspere murder. Will the death of the potential informant, Irena, send him backwards in his investigation or has he finally figured out the next recourse to take?

Last episode, Ray (Colin Farrell) confronted Frank about the wrong information he gave him years ago about the person who raped his wife. They ended up making a deal. Frank would find the man who duped him with false leads, while Ray would search for Caspere's hard drive so Frank could make his deal.

Meanwhile, Ani got herself invited to the elite prostitution party to look for possible leads to the investigation. She was made to take ecstasy, however, and would have been raped by a rich man named Mr. Wyman (Brett Rice). She managed to escape, though, and brought with her Vera (Miranda Rae Mayo), the subject of the missing person's case she had been working on. 

Paul, for his part, found the break they were looking for while searching for clues in the mansion's study. He discovered a new contract for the high-speed rail line drawn up by Osip (Timothy V. Murphy) for his new buyer. As for Ray, he was told by his ex-wife to take a paternity test and that any visit he would have with with Chad (Tervor Larcom) would be supervised.

"True Detective" airs Sundays at 9 p.m. EST on HBO.