'Law & Order' Revival Season Finale Features 'SVU' Guest Star

The Law & Order Season 21 finale features the first appearance of Captain Olivia Benson since the mothership series' return. Law & Order: Special Victims Unit star Mariska Hargitay occasionally popped up on Law & Order during its original run and has shared scenes with Sam Waterston on SVU. This time, she helped Det. Frank Cosgrove solve a crime. The finale airs Thursday at 8 p.m. ET on NBC.

In "Black and Blue," a New York Police Department detective is murdered, so the detectives prepare for the worst. Cosgrove (Jeffrey Donovan) asks Benson to help solve the case of his friend's murder. Later on, D.A. Jack McCoy (Waterston) and Executive Assistant District Attorney Nolan Price (Hugh Dancy) disagree on how to prosecute the suspect. Throughout the season, Price and McCoy have repeatedly disagreed on cases, forcing A.D.A. Samantha Maroun (Odelya Halevi) to step in and mediate.

Halevi, who grew up wanting to be a lawyer, told Entertainment Tonight that the "stakes are very high" in the finale. "Without giving too much away, I can say that the story in the final episode of season 21 is very personal to all the characters and in turn will start some new and transformative conversations," Halevi said of the finale. "There also may be a shift in one of Maroun's important relationships."

Law & Order mastermind Dick Wolf and showrunner Rick Eid did not keep fans guessing as to why Maroun connects so closely with victims. In the Season 21 premiere, Maroun told a jury her sister was raped and murdered. Police knew who the killer was, but prosecutors were unable to make the charges stick. Price pushed Maroun to tell this story in court to help prosecute Nicole Bell.

"She relates to the victims and she relates to some of the defendants... And she has had thoughts about killing the person [who raped her sister]. And so, she relates to people who have those fantasies," Halevi told ET. However, Maroun knows the difference between "having those fantasies and actually doing something about it, which is criminal."

Halevi previously told PopCulture.com that Maroun's backstory is what really attracted her to the part. I realized in my audition that there was going to be a closing argument for Maroun in the first episode and a whole backstory, and I was blown away by that because that's something that didn't really happen before in the original Law & Order," she said. "So that was really, really exciting and nerve-wracking at the same time, but mostly exciting."

The Law & Order revival has already featured familiar faces, including A.D.A. Jamie Ross, played again by Carey Lowell. Dylan Baker also returned as a defense attorney in one episode. Hargitay appeared in three episodes of Law & Order during its original run and she last shared the screen with Waterston in 2018 when he appeared in the SVU episode "The Undiscovered Country." The current seasons of Law & Order, SVU, and Law & Order: Organized Crime are available to stream on Hulu and Peacock. All three were renewed for next season