EXCLUSIVE: Behind the Scenes of Mariska Hargitay & Anthony Edwards' 'ER' Reunion on 'SVU'

“To work together again is an honor and a joy,” Mariska Hargitay tells ET from the set of Law & Order: SVUin late September. The long-running show’s star and executive producer is referring to her reunion with Anthony Edwards, whom she appeared opposite nearly 20 years prior on ER. The two will once again share the screen on an upcoming episode of SVU. “I’ve actually wanted Tony to come on the show for probably 12 years.” 
Fans of NBC’s long-running medical drama will remember Hargitay from ER’s fourth season, on which she played Cynthia Hooper, who despite her inexperience is hired by Dr. Mark Greene (Edwards) to be a desk clerk at Chicago’s County General Hospital. The two eventually end up in a dysfunctional romance that comes to a head when Greene flies to California to be with his sick mother and Hooper makes a surprise visit. MORE: Mariska Hargitay and 'SVU' Cast on Joe Biden's 'Dream Come True' Guest Appearance
While Hargitay was only on for 13 episodes, both stars fondly remember their time together, recalling a time when they filmed a drunk scene with tequila shots. “That was very much outside my comfort zone,” Hargitay says, crediting Edwards for protecting her as an actor. “I was so nervous and hadn’t done something like that … I remember going, ‘I am so grateful for this feeling of safety. I want to provide it [to someone else], if I am ever lucky enough to be in his position.’”  
Photo: NBC
By the time she joined ER, Hargitay had been working on TV for over a decade. But for her, it was the first time things started really coming together. A year later, the actor would star on Law & Order: SVU, the Law & Order franchise’s first spinoff. “It was at the beginning of something. The trajectory of my life and career -- and certainly me as an actor -- changed from being on that show and working with all these amazing actors,” Hargitay says. “It was incredible education and an incredible gift.”
So, why did it take so long to reunite onscreen? “It all happens for a reason and this is the right time to be here,” Edwards says. “I think it’s just the timing -- and the timing is perfect.”  MORE: 'SVU' Stars Christopher Meloni and Mariska Hargitay Reunite for Sweet Selflie
Now, in the show’s 18th season, Edwards guest stars as Sgt. Patrick Griffin, a cop who was Lt. Olivia Benson’s (Hargitay) first partner out of the Academy. Griffin makes a surprise return to Benson’s life when his son is suspected of rape, forcing Benson to choose between loyalty and duty. The episode, “Rape Interrupted,” airs Wednesday, Oct. 26, replacing the controversial Donald Trump-inspired episode “Unstoppable,” which was pushed until after the election. 
“What’s intriguing to me is that you’ve got people that have to help each other. But there are rules and the line of that keeps moving,” Edwards says of the dynamic between Griffin and Benson, who finds herself put in a difficult situation. “We had a certain relationship then, and now here we are in a situation in which I’m in great need and I’m drawing on this old friendship.”
For both, it’s fun playing in this gray area -- a dynamic that is very different from their arc on ER. “It’s not clear or black and white,” Edward says. “For actors, that’s fun because we get to try and find out what it is.” 
Photo: NBC
Of course, this is not the first time ER has crossed over with SVU. Neal Baer, who wrote for ER including an episode starring Hargitay, was the showrunner for SVU for 10 seasons. Meanwhile, Alex Kingston, Erik Palladino, John Stamos, Kellie Martin, Maria Bello, Michael Michele, Ming-Na and Scott Grimes all have appeared on SVU in various guest-starringroles. 
Gloria Reuben, who played Jeanie Boulet during the first six seasons of ER, later appeared as two different characters on SVU and tells ET she’s an admirer of what Hargitay and the show has become. “It's been exciting to see Mariska really take command and really be a leader for such a terrific show. She's really carried the emotional weight of the show for a long time. She's a female warrior in that regard,” Reuben says, adding that she hopes her character, ADA Christine Danielson, returns someday.  MORE: 20 Years Later and We Still Love You, 'ER'
While Edwards’ appearance is limited to this one episode, he hasn’t ruled out a return to the SVU set. “Maybe I will be able to come back and keep playing,” he says. Though, if Hargitay has her way, she may tap into his skills as a director. “First, I was trying to get him on here as a director,” she reveals. 
Edwards, who directed four episodes of ER, also helmed My Dead Boyfriend starring Heather Graham, in theaters and on demand Nov. 4. “I’m just so thankful,” he says of the “little independent comedy I made.” Law & Order: SVU airs Wednesdays at 9 p.m. ET on NBC.