It’s the eternal question: When someone dies, is he or she ever really gone? On “Grey’s Anatomy,” the answer is no. People from seasons past might be dead, but never forgotten. Always mixing work and home life as they do, there is nary a place anyone can go without being reminded of their lost loved ones.

On Thursday night (Nov. 10), a particularly artistic bottle episode brought back an entire operating room full of forgone characters, including Derek Shepherd (Patrick Dempsey).

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Did Derek really return during “The Room Where it Happens”? No. Season 1 footage provided a memories for Meredith (Ellen Pompeo), which she — like the rest of the cast — half-believed she was seeing, during an exhaustive surgery after two sleepless days and nights.

Scrubbing out in the same room she first met Derek — the man she would marry with a post-it note, the handsome brain surgeon who became the father of her three children, the man she mistook briefly for the sun — it was impossible not to yearn right alongside Meredith for McDreamy to somehow just be alive again. But while “Grey’s” is a particularly soapy drama, there’s nowhere in the story for Derek’s return.

mcdreamy gif Derek returns to a Greys Anatomy haunted by its past

However, there is an open door to the idea that Megan (Bridget Regan), Owen’s sister is not actually dead. She’s been described as having died in a helicopter crash, but we’re repeatedly reminded they never found a body. Meredith has had two half-sisters show up out of the blue, so it would be right on brand for Megan to somehow waltz into Grey Sloan one day.

Where’s she been all this time? Why hasn’t she contacted her brother — or Riggs (Nathan Henderson), her husband? All good questions. Finding out those answers, plus the dramatic wrench it would throw into the romantic mess that is Maggie, Meredith, and Riggs — well, that would be a beautiful disaster.

bridget regan, grey's anatomy

Thankfully, the series hasn’t ever taken the ghost theme quite as far as it did with Denny (Jeffrey Dean Morgan), but if this Shondaland show ever wants to give us more hallucinations, we’d love to see George (T.R. Knight), Lexie (Chyler Leigh), or McSteamy (Eric Dane), please. And even though she’s not dead, the return of Izzy (Katherine Heigl) would be everything. It’s hard to say whether Karev (Justin Chambers) could survive such a surprise — he’s barely keeping it together as it is — but for a show nearing the fall finale of Season 13, it makes sense the show isn’t holding back on revisiting its own history.

We think of this as a soap opera trope, continually revisiting and reappearing characters like Leah (Tessa Ferrer) or this episode’s many callbacks — but it’s actually more realistic than a regular televisual narrative. Most of us aren’t lucky (or unlucky) enough to have just one romance over the course of our loves. So while it’s doubtful that we’ll ever be privy to, say, the nonstop additions to Meredith’s family tree, inconvenient exes and complicated/complicating histories aren’t just a hallmark of “Grey’s” — they’re a fact of life.

addison gif Derek returns to a Greys Anatomy haunted by its past

Even Kate Walsh, who memorably played Addison Montgomery on the long running series before moving on to star in spin-off “Private Practice,” doesn’t deny she could one day make a return. “There’s always a possibility for a special thing,” she told Screener. ” I’d do anything for Shonda. She’s incredible.” That dedication to the show’s creator alone explains why so many actors are willing to return.

Very few series have been on the air as long as “Grey’s,” and churning out 22 episodes a season is a dying custom — one Shonda is helping phase out! — but “Grey’s” own, highly notable reverence for its own history, with its weekly references to plane crashes and active shooters (not to mention Izzy, Yang and even Isaiah Washington’s Dr. Burke) is a study of lives in motion, and as we saw this week, that means the past sixty years remain in play.

There’s no reason to expect old favorites won’t keep popping up — and if that means one day the prodigal return, or at least meaningful visit, from Christina Yang (Sandra Oh)… Uh, we won’t be complaining.

“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