Viewers knew coming into Thursday night’s (March 30) episode of “Grey’s Anatomy” that it would be an emotional one. And even though Maggie (Kelly McCreary) getting up to open the window of her mother’s hospital room was the most obvious cliche moment for Diane Pierce (LaTanya Richardson) to then pass away, it didn’t make her death any less hard heartbreaking to watch. One can prepare for a loved one to die for months, or even years, and yet, when it finally happens, it still always comes as an emotional shock.

As the first time directing for Ellen Pompeo, after 13 seasons, “Be Still, My Heart” feels intimately personal. The fact that she is the heart and center of the show, plays Maggie’s sister, and delivered the bookending monologues — about Meredith’s relationship with her own complicated mother — it’s impossible not to feel implicated in the metanarrative interactions of life and art. Maggie, Meredith, Richard (James Pickens, Jr.) and Diane have four lifetimes’ worth of intimate interconnection, giving the episode as a whole a feeling of largeness beyond its constituent parts: It connects past and present, old cast and new, in a way that binds them all together.

RELATED: There is nothing worse on ‘Grey’s’ than when Maggie Pierce is sad, even if you knew it was coming

Perhaps that’s why we couldn’t shake the odd feeling that the structure of the episode, in part, represents another way for Meredith to support her sister, even as Maggie is pushing her away: As the actress portraying Meredith, Pompeo is a shoulder for Maggie to cry on, eventually. Off screen working as the episode’s director, she helps guide McCreary through these powerful and difficult emotional scenes. We could almost envision Meredith Grey somehow calling up Shonda Rhimes, begging to direct this episode because she knew it would be so difficult for Maggie to get through. Constructing the safest universe possible for her; being there for her even when, in-story, Meredith cannot.

As a director, even the one with the most on-the-job training of anyone alive, Pompeo’s eye is hit and miss: Beautiful moments abound, and powerful performances, but a certain lack of ambition, too. The first half of the episode clips away at an impressive pace — and as time jumps ahead, it becomes clear Diane won’t survive the hour.

It’s an unexpected move: Most key deaths on the series are drawn out through an entire season… And sometimes, don’t even end then. (Hey, Denny!)  It wasn’t that long ago we discovered Diane’s breast cancer diagnosis, and it was just last week that Maggie finally found out.

maggie greys anatomy Ellen Pompeos first time directing Greys Anatomy    a heartfelt mixed bag, but powerful

When most characters die, there’s an entire funeral procession and they’re laid to rest — or sometimes, as with Meredith’s mother Ellis, get their ashes unceremoniously dumped in the sink of O.R. 2. But since she’s such an important part of this story, let’s take a moment to remember just how wonderful Ellis Grey (Kate Burton) was as a mother.

greys anatomy ellis Ellen Pompeos first time directing Greys Anatomy    a heartfelt mixed bag, but powerful

While the ashes are a laughably ridiculous memory during a family dinner, knowing Ellis as we do, Maggie later uses this same story to twist the knife during a later confrontation: Coming to terms with the fact that the clinical trials she insisted her mother try out are indeed killing her, Meredith begs her to stop the tortuous treatment. Maggie cuts her off saying, “I love my mother enough to not say, ‘Screw it’ and pour her down a damn drain.”

At which point we remember, if we hadn’t before, that Ellis was Maggie’s mother, too: Maggie shows us this week that she respects and loves Richard on many levels, but when she’s up against the wall, it’s the father who raised her for whom she desperately wishes. To her, Ellis can’t ever be much more than a punchline and, abstractly, half of Maggie’s genius.

RELATED: ‘Winter is coming’ on ‘Grey’s Anatomy’: Bailey replaces Meredith with… Kepner?

And likewise, Meredith can’t ever fully comprehend Maggie’s pain here: She barely got more from Ellis than Maggie, who never met her at all… And unlike Maggie, never lucked into a Diane. She raised herself, and it shows.

Only siblings know how to say the exact words, at just the right moment, to sufficiently rip you apart: After all Meredith has lived through since losing Ellis, we have to assume she’d process that death quite differently. But it’s also those same siblings who are there for you when no other sane person on the planet would be. These three women will definitely be okay.

sister greys anatomy gif Ellen Pompeos first time directing Greys Anatomy    a heartfelt mixed bag, but powerful

Meredith is now using this difficult time as her latest defense against a relationship with Riggs (Nathan Henderson), but it only makes us more worried the longer Meredith hides this tryst from her sister — especially when Riggs’ comfort is the only thing that gets through to her. Diane lied about her cancer for months, everyone else has been lying for weeks — and finding out the one person still alive she thought she could depend on has also has been lying? Maggie’s reaction will be devastating no matter its origin.

Moments that didn’t quite work in this emotional episode include the final shot of the three sisters eating lasagna — meaningful in this context, as it means Maggie (all of them) will have to come to terms with taking care of herself on some level — in silence. Taking away the background music works best when used sparingly. Maggie crying after having to shut her mother’s still open dead eyes, that incredibly disturbing scene in which viewers were left wondering whether Diane might still be alive — but oh my god why isn’t she blinking? — would have been a better place for that silence, perhaps.

We enjoyed the fact that Meredith, Maggie and Amelia (Caterina Scorsone) didn’t have to go through motions of small talk, are close enough to comfortably sit with each other in silence eating the last lasagna Diane ever cooked — but the subsequent helicopter camera angle took us out of that feeling entirely, softening the final punch of that last voice-over: “Goodbye, Mother.”

meredith gif greys anatomy Ellen Pompeos first time directing Greys Anatomy    a heartfelt mixed bag, but powerful

Maggie will be struggling with this loss for awhile. It seems right on brand for her character to want to jump back into work — but if she isn’t quite ready, and gets shaky in the OR, the only place she feels safe and confident, her home now more than ever… Things might start looking even more grim for this gifted cardiac surgeon.

We’re already regretting the fact that “Grey’s” has noticed how moving and exquisite McCreary’s performances can be, especially under stress — and almost certain it will get worse for her before it gets better. (Although, we assume, not before Jerrika Hinton’s fantastic-but-departing Stephanie Edwards succumbs to her own yips, which could keep Maggie safe for a while.)

Both sisters saying farewell to their mothers, tying together all the threads throughout the hour comparing and contrasting Ellis and Diane’s deaths, works best through Meredith’s eyes — and while the monologue is a moving way to preserve that idea, and we know it would have been impossible to pull off (Chandra Wilson’s episodes are always Bailey-lite, but always make her moments count triple-hard to make up for it, for example)… It’s not until Diane departs that Meredith can let go of worrying at her mother’s final words, “Tell Meredith don’t…”

Diane’s passing is peaceful and the best she could have hoped for, while Ellis’s death was as brutal and intense as the life that preceded it. But “tell Meredith don’t” is such a powerful mystery because it is a blank space, into which we and Meredith can project nearly anything at all. Letting go of those words is laying her mother to rest — but it’s also pouring every one of the infinite negations it contains down the drain, too.

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“Make mistakes,” Diane urges her daughter. “Tell Meredith don’t,” Ellis urges hers. And by letting go of one, Meredith may just be taking up the other.

And we couldn’t be happier for her: What a perfect symbol of all we lose, good and bad, formative and deforming, joyful and traumatic, when we’re forced to let anyone go. Never quite getting to the end of a story is painful — but when that story is what’s hurting you, you must have faith that it’s worth accepting.

Goodbye, Diane — and goodbye, Ellis. Thank you for taking time out of your brilliant, lifelong rampage to provide us with not one but two of the most magnificent, most brilliant, bravest women we’ve ever been lucky enough to know.

“Grey’s Anatomy” airs on Thursday nights at 8 p.m. ET/PT on ABC.

Posted by:Emily Bicks

Freelance writer in LA. Sometimes, I'm on camera. And sometimes I'm not. Twitter: @missbicks