Actress Kellie Martin has been in any number of memorable projects. She’s been working since she was 7, which means she has stories about working with both Lucille Ball (on the legendary actress’s final TV show, Life with Lucy) and up-and-coming teenage actress Kiernan Shipka (on the Hallmark Channel movie Smooch and the show Mad Men).

But for many ’90s TV fans — such as myself — Martin will be indelibly etched in their memories for two parts: the soulful teenager Becca on the family drama Life Goes On (which ran from 1989 to 1993) and med student Lucy on the mega-hit ER, on which she starred from 1998 to 2000.

In particular, ER is stuck in TV fans’ memories because of how Martin left the series, in a terrifying, indelible pair of episodes in which she and her mentor, Dr. John Carter (Noah Wyle), are stabbed by a patient. The other doctors scramble to save the lives of both, but only Carter makes it out. Lucy perishes on the operating table. (You can take a look at the memorably terrifying reveal of the attack here.)

Martin, who’s now starring in TBS’s new comedy The Guest Book, joined me on the latest episode of my podcast, I Think You’re Interesting, to talk about her long and varied career — and it turns out the story of her time on ER had even more to it than I had already thought.

For starters, Martin took the job amid a family tragedy. She says:

My sister got lupus and passed away a week before I started working on ER. So I started that show as an absolute wreck. Literally, they pushed for a week for me, because they wanted to give me a week. So I don’t remember much about ER. I really was on autopilot. ... Being in a hospital after having been in a hospital for months for real with my sister was super weird and felt really wrong. I never allowed myself to really enjoy it and go there.

Martin made her way through the trying time with the help of her then-boyfriend, now-husband and a reliance on the technique she’d been honing since her first acting jobs as a child.

My boyfriend kept saying to me, “You’re a professional.” So all I did was my job. I went to work. I did my job. I kept it all in, kept it together, kept a lid on it. I’m good at working on a television show. I know how to do that. If nothing else, I can do that. And that’s what I did.

What’s more, as Martin began her job in the midst of mourning her sister, she was joined on the set of ER by her TV mom from Life Goes On, Patti LuPone. “She flew out to be with me on set. She sat on the set of ER, sat in my little chair, and just was there for me,” Martin says late in the podcast.

So when it came time for Lucy to die nearly two years after she’d started on the show, Martin experienced a variety of emotions. She says:

When [showrunner] John Wells approached me to have Lucy leave, I was a little relieved, just because I kind of couldn’t keep it up, and so it was a blessing in disguise, even though I took it as I was being fired. ... I’m so glad it was an awesome moment in television, but it was really hard for me. And it was really hard for the other actors, because they did not know I was leaving until they read the script, so it was really sad. Alex Kingston, there’s this scene where I diagnose myself. I put my hand over my [trachea], and I say, “P.E.,” like pulmonary embolism, and she’s in that scene with me. She couldn’t get through the scene because she kept sobbing. ... It was hard, and my last scene that I ever shot on ER was when I was laying on the slab dead, and the director, Jonathan Kaplan, came up, and he whispered to me, “You’re wrapped,” and I just grabbed my husband’s hand, and I left. I didn’t even say goodbye to people. It was really hard for me.

Martin has many more stories like that about so many of her most memorable roles — including, yes, her voice work in A Goofy Movie, where she voiced Roxanne — and she ended up being one of my favorite guests on the show. Give it a listen, and I think you’ll see what I mean.

To hear more interviews with fascinating people from the world of arts and culture — from powerful showrunners to web series creators to documentary filmmakers — check out the I Think You’re Interesting archives.