Assistant District Attorney Rafael Barba (Raúl Esparza) will butt heads with an unlikely foe in the upcoming season premiere of "Law & Order: Special Victims Unit."

The synopsis (as per Yahoo News) for the first episode of the new installment is out and viewers can expect that it is going to be tension-filled. The SVU will take on a new case involving a lost little boy who was abandoned in a park. As the authorities' search for his mother draws in the media, Barba will find himself pitted against Lt. Olivia Benson (Mariska Hargitay). Friction is said to rise between them when they take different sides on the case. This will not be the first time that Barba and Benson had differences in opinion. The promo photo shows, however, that there is going to be a major battle in court between the two.

Meanwhile, one of the guest stars who will join the cast for the new season is U.S. Vice President Joe Biden. He is set to appear in one of the upcoming episodes that will air in September.

Biden, just like Hargitay, is a known advocate on violence against women. In May, the actress expressed how grateful she was to the show for opening her eyes to what was truly happening in the world. Hargitay is the founder of Joyful Heart, an organization promoting awareness about the said issue.

"It's a very powerful show that is dealing with such important and real, current issues that are potentially life-saving. So I don't know if it gets better than that. Right? Now the Foundation and the show have such a beautiful marriage. They completely support each other and it's been so important telling these stories and then continuing the work in real life with our advocacy and changing laws, changing societal attitudes and hopefully cleaning up the rape kit backlog," Hargitay told E! News.

"Law & Order: Special Victims Unit" season 18 will premiere on Wednesday, Sept. 21, at 9 p.m. EDT on NBC.