Barba (Raul Esparza) will take on the toughest case yet of his long career in the upcoming episode of "Law & Order: Special Victims Unit."

In the episode titled "Imposter," the synopsis reveals (as per CarterMatt) that the Assistant District Attorney (ADA) will get a difficult case involving a supposed rape. A man (to be played by Wallace Langham) is being accused of molesting a vulnerable woman. He allegedly posed as a popular individual to make her come to him. The victim, who is a wife and a mother, and her family are suing the offender, but the latter's lawyer is preparing a good defense. They are going to make the incident appear as if the woman was not forced by the accused to do it with him.

Barba, however, is convinced that the evidences point to rape. Proving this will be very difficult though and he will be facing the other side's powerful attorney (to be played by Callie Thorne), who will make sure that her client will not go to jail. Barba also has to deal with a judge (to be played by Vincent Curatola) who is also doubtful if the claims of the victim are true or not. He will have to think of a good strategy to prove their case or a potential rapist may walk away.

Last episode, Vice President Biden guest starred as himself to praise the work of Benson (Mariska Hargitay) and her team and to address the issue on the time lag in testing rape kits. He mentioned the man who was exonerated after 16 years of being in jail because of an untested kit. After the press conference, the "suspect" approached Benson. He and the rape victim were reportedly friends. The woman's daughter was getting married and he was invited to the ceremony. That night, the engaged woman was raped. Clues point to the exonerated man and the SVU was able to prove it in court.

"Law & Order: Special Victims Unit" airs Wednesdays, 9 p.m. EST on NBC.