The Emmy-nominated and Golden Globe winning actress, 59, stopped by NBC’s Today on Friday, Oct. 11, to discuss her new role as Lt. Jessica Brady on the network’s long-running police procedural.

But as host Savannah Guthrie pointed out, Tierney’s history with Law & Order goes all the way back to 1991, when the then-26-year-old actress guest-starred as the sister of a victim in a season 2 episode.

Tierney displayed some truly impressive recall of the episode’s plot. “The story was my sister was an actress and my mother was a big stage mom, and the mom was pushing the sister to do adult films,” she explained. “And then, so, the sister committed suicide, and the mom was charged with manslaughter.”

The hosts played clips from the episode for Tierney, and Al Roker asked what advice she would give to her younger self.

“Oh, I would just tell her to relax, man,” Tierney joked. “Look, you’ll be fine!”

Tierney also discussed what it was like playing a tense scene opposite Law & Order: SVU star Mariska Hargitay, who guest-starred in the most recent episode of Law & Order.

“It was great. It was only the second episode, so it was really fun for her to come over,” Tierney said. “She has a really big, very warm personality. Plus, everyone’s stoked when Olivia comes over to our thing. It was really fun, and it’s fun that the characters … kind of butt up against each other.”

And, of course, you can’t talk to Tierney without asking her to look back on ER, which just marked the 30th anniversary of its pilot episode in September. Tierney first appeared as Dr. Abby Lockhart on the series 25 years ago next month, in a November 1999 Thanksgiving episode, before joining the show’s regular cast in February 2000.

“It’s a great, great show,” Tierney said of ER. “And I did come in in the middle, but I think it continued to be great. People watched it during the pandemic, and all new generations learned about it. It’s such a really high quality, great show and I do keep in touch with sort of the last half of the cast. Like, Linda Cardellini’s a good friend of mine, Parminder [Nagra], John Stamos.”

“It was a big deal,” she added. “It was eight years of my life that I was with these people, so it was a real bonding experience.”