'Grey's Anatomy' Producer on Thatcher's Goodbye and Catherine's Harrowing Cancer Journey (Exclusive)

Warning: Spoiler alert! Do not proceed if you have not watched Thursday's episode of Grey's Anatomy.

Grey's Anatomy looked to its writers' room for real-life inspiration behind Catherine Avery's (Debbie Allen) harrowing cancer journey. In a November episode, Catherine learned she had been diagnosed with a rare form of bone cancer, and on Thursday's episode, she went under the knife for a risky procedure to remove the large tumor on her spine. While Amelia (Caterina Scorsone) and Koracick (Greg Germann) weren't successful in removing the entire tumor, like they had promised -- only 95 percent of it -- Catherine persevered through the surgery, grateful to be alive and adopting a new perspective on life.

Catherine's cancer storyline is inspired by co-executive producer Elisabeth R. Finch, who wrote Thursday's emotional hour, and her experience. Finch was diagnosed in her 30s with a rare bone cancer, like Catherine on the show, and continues to live with it. Having a character who wasn't miraculously "cured" of cancer through surgery was an important reality of life Grey's showrunner Krista Vernoff and Finch wanted to convey because it has rarely been portrayed on television.

"Because my illness is chronic, I'm considered a person with a disability, but every time we see cancer stories, they're either life or death, there is very little in-between. I was very interested in telling a story where someone is living with it day to day and still having a full healthy friend life, work life, love life," Finch told ET, adding that Catherine's story is only beginning. "We get to watch Catherine move forward and move through recovery and see what that's like and see how she feels a month from now, six months from now, a year from now, both emotionally and physically. We get to watch a person who is living with cancer on television."

In the same episode, Meredith (Ellen Pompeo) paid a visit to her estranged father, Thatcher (Jeff Perry), who was dying of terminal cancer. Their charged reunion was a monumental moment for Grey's, as it had been eight seasons since Thatcher was last seen in the universe. (His last episode had come in season seven.) And though their time together was brief, they managed to air out some of their baggage, connect on a meaningful level (see: the revelation about Thatcher attending Derek's funeral) and a heartbreaking, bittersweet final moment between father and daughter as Thatcher says his final farewell.

Here, Finch spoke with ET about channeling her real-life cancer journey through Catherine, why it was important for her not to be completely cancer-free by the end of the episode, how Thatcher's death impacts Meredith moving forward and a potential new Grey Sloan pairing.

ET: Why did you want to incorporate your own real-life experience with cancer and write it into Catherine's story?

Elisabeth R. Finch: I was reluctant to talk about my own cancer, to write a story about my personal experience. I've always been very open in the room; I've been here for five years and they've seen me through every phase of my illness. But when it came to filtering that into an episode of Grey's, I wasn't quite certain what I wanted to say or how I wanted to say it until there was one moment in the writers' room where I was having a casual conversation about how much I hated the language surrounding cancer, how much we hear the words "winning," "losing," "she lost her battle," "we have to fight," "we have to beat this." It didn't look anything like my life.

Krista approached me and said, "Why don't we write a story about that? Why don't we write a story about someone whose experience mirrors yours, someone who is living with cancer, and more or less a chronic condition?" It was something that we haven't seen on TV before. Because my illness is chronic, I'm considered a person with a disability, but every time we see cancer stories, they're either life or death, there is very little in-between. I was very interested in telling a story where someone is living with it day to day and still having a full healthy friend life, work life, love life, and so Catherine became the person who took on that storyline.

And Meredith even says that at the end of the episode -- that there's no winning, no battling or losing when it comes to this experience. Was there a specific moment or scene that was the toughest for you to get down on paper?

Writing it was really easy for me because I tend to separate or not recognize how much of myself I'm putting in stories. It's only when it's reflected back to me that I really take it in, and this was no different. But towards the end of the shoot, when Catherine wakes up and is grateful, when everyone's anticipating her disappointment, her fear, her anger or her devastation, and she looks at them and they're all devastated, and she says, "No, this is a cause for celebration! I get to live!" And Catherine starts to list all of the good things in her life she'll get to experience. I sat there and heard it over and over and over again, and that was the first time I took it in because it was the first time I'd seen a version of myself reflected back at me. I'd never seen anything that talked about cancer the way I had lived it, not in any movie, not in any television episode, or book. That was the most difficult day to take in.

In that same scene, Catherine says "miracles aren't always punctuation marks, but they're worth celebrating too." That line really struck a chord because it illuminated the realities of the real world, where not everything is wrapped up in a bow. Although, on TV sometimes, it's presented that way a lot.

It is and it can be frustrating. What's nice about having Catherine not be a patient is we can have someone who's lived in our world, we don't have to wrap it up in a pretty bow at the end of the episode. We get to watch Catherine move forward and move through recovery and see what that's like and see how she feels a month from now, six months from now, a year from now, both emotionally and physically. We get to watch a person who is living with cancer on television. I get thrown in a scanner every couple months here and there, I have to go to doctors appointments every once in a while, and in between, I have a full-time job, a family I love, friends I love and a big full life. And so does Catherine. It isn't finite.

What are you looking forward to exploring on the show in relation to Catherine's progress?

When we started planning this story, it was always of interest of me to show Catherine make it through the worst of the surgery, and then walk around in the normal world. I am not always at a crisis point. Every once in a while, something pops up, a scan looks abnormal, and I'm curious about it, and I get more tests, and sometimes I go through six months of boring, I go through one month of interesting in the cancer world, where all of a sudden everyone's looking at things closely. I think normalizing what it is to be a person with chronic illness is something we don't often get to see on TV, and Catherine gets to be the face of that and the voice of that, where it's not always about that. It's about her big, wonderful, brilliant life. And every once in a while, there's maintenance and things to take care of.

Switching gears to the other storyline of the episode: Meredith visiting her dad, Thatcher, which is such a big moment for the show. Since it's been a while since we've seen Thatcher, did you have a checklist for what you wanted them to talk out or go through?

Meredith and Thatcher have been through so much and not a lot of it together. They've experienced huge losses and they haven't really partnered through it together. They've been separated, either by his choice or by her lack of awareness that he tried and reached out, but the end result is these two people, who clearly care for one another and there's a lot of love there, haven't spent much of their lives together. It could have been different and there's a bittersweet, devastating undertone to that, that they've run out of time, that they have this day and she walks in there with one foot out the door. I don't think she knows what to expect or how she's gonna feel, but she's not going in thinking there's going to be big, lovely, warm moments.

What did you want to convey in the brief time Meredith and Thatcher attempt to reconnect?

What happens often in those situations is you try your best to connect to the person in front of you, to try and put aside some of those differences or to work through them as much as you can. There wasn't enough time for them to have real, true closure. I think there is understanding. I think there are moments of grace and they get to laugh a bit, and they get to reminisce about their experiences with Ellis. I love that Meredith learns something new, a side of Ellis that she had never seen, about the day she was born -- something she had never heard about. I wanted these two people to be in a room and do the very best that they can with the time that they have left. It's not perfect and there's no time for perfect, but there's a little bit of time to connect.

Thatcher reveals he was there at Derek's funeral and recounts what happened. Why was it important for that to be a point made in this episode, that he was there in the back and that he was there for his daughter?

Thatcher has been someone who didn't fight for Meredith, or she felt he didn't fight for her, that Ellis took her away and he just kind of stayed away and didn't try too hard. Krista Vernoff and I talked a lot about what Thatcher has been up to all these years. Where has he been? Big things have happened; Lexie died, Derek died and it was interesting to both of us to imagine a Thatcher who, as Meredith said, got his head out of his own a**, and stopped behaving like a perpetual victim -- that saw himself as a man with agency and who would get up and do something good for the world, or would hear about his daughter in Greece and would do everything he can to go be there. It's heartbreaking that she never knew it, that he never really pushed more than showing up to make her aware of his presence.

But, that happens sometimes in those moments of grief that you don't quite know what to do, but it was important for us to show that Thatcher had changed, had wanted to change and had made an effort to try and connect and it fell short. There's something really heartbreaking about that because maybe that would have changed things, maybe that would have given them more time together, maybe [he] would have know the grandchildren more. We're not gonna know. But Meredith at least goes there and finds out that her dad did try for her, did try in his own way [to] fight for her and try and go and be there for her when she needed him.

Meredith has suffered so much loss. You mentioned Lexie, Derek, Ellis and now Thatcher. How does Thatcher's death affect Meredith differently than those of her husband and her other family members?

She's known about Thatcher dying for a really long time, so she's had some time to process it. She had one complicated, beautiful, big-hearted, strange, heartbreaking day with him, and she had a chance to have a little bit of closure, a little bit of grace. When she goes home to her children and has gifts for them and says that she's going to be OK, I think that that's something that we can feel, because she had an opportunity to know what was happening before it happened. She didn't have that experience with Derek, she didn't have that experience with Lexie, she didn't really have the time to process that grief and to say the things she wanted to say beforehand. This time she does, so that does a lot for a person, to be able to say the things they wanted to when they have the chance.

It seemed like the seeds were being planted for a potential pairing between Teddy and Koracick. Is that something that was intentionally placed in this episode?

I can say right now they have a really fun energy. He is so unpredictable and unexpected, and I love how that confounds Teddy and delights Teddy, and I can't wait to see more of that.

Grey's Anatomy airs Thursdays at 8 p.m. ET/PT on ABC.

RELATED CONTENT:

'Grey's Anatomy': Lindsay Wagner to Return as Alex's Mother in Season 15 (Exclusive)

'Grey's Anatomy' Gets More Episodes for Historic Season 15

'Grey's Anatomy' Casts Jennifer Grey in Top-Secret Season 15 Role

Related Articles:

• Hollywood's Best Bikini Bods Over 40

• Biggest Celebrity Breakups of 2018

• Celebrities in Their Underwear