300REASONS WHY

‘Grey's Anatomy’ conquers episodic plateau

‘Grey’s Anatomy” has reached its 300th episode — joining an elite group of prime-time series including “CSI,” “Law & Order,” “ER” and “Gunsmoke.”

So when series creator Shonda Rhimes told cast member and producer Debbie Allen that she should direct Thursday night’s Very Special Episode, Allen realized the stakes were high.

“Oh, no pressure, no pressure!” says Allen, who’s directed more than a dozen “Grey’s” installments, as well as episodes of shows like “Empire” and “Jane

the Virgin.” She says there wasn’t room for jitters, or even for wistful thinking.

“I wasn’t nervous. There’s no time to be emotional when you’re directing and guiding a ship that has 250 people on it,” says Allen, who plays Dr. Catherine Avery on the show.

Instead she embraced the 300th episode as “a real benchmark in the legacy” of Rhimes, whose series is in its 14th season.

“As a woman director and producer to be in a field at this time when women have such a strong voice, it felt good,” she says.

The episode will offer “a wink” to doctors past, she says, when a roller coaster accident sends young victims to Grey Sloan Memorial Hospital. A teaser after last week’s episode showed two patients who bear a striking resemblance to Dr. George O’Malley (played by T.R. Knight, who was killed off in 2009) and Cristina Yang, portrayed by Sandra Oh, who left “Grey’s” in 2014.

“Doppelgängers are a big part of the story,” Allen says. “I call this episode our Hubble Telescope, where you can look into the past and the future at the same time.” However, nostalgic viewers shouldn’t expect the return of, say, fan fave Dr. Derek “McDreamy” Shepherd (Patrick Dempsey), who perished in a car crash in Season 11. “Derek died, so he can’t come back,” Allen says. “But we think of him. We think of him.”

And Derek’s widow, Dr. Meredith Grey (Ellen Pompeo), is impacted by the episode’s turn of events.

“Well, it’s always about Meredith, isn’t it?” Allen says. “At the end of the day, what happens to Meredith is of the most interest to the fans.”

The 300th episode was also a time for the cast and crew to embrace the show’s past with a party last Saturday in LA. “There was a lot of laughter, a lot of reminiscing,” Allen says. “We put up pictures from the first episode until now and it was like being in a museum. It was like a family reunion.”

Allen mentions “a very dramatic ending” but stops short of specifics. “I’d get in trouble,” she says, noting that Rhimes’ production company, Shondaland, uses a roller coaster as its logo. “I don’t want to be under that roller coaster; I want to stay on it.”

After light prodding, she teases a “real big” surprise for fans. “It involves somebody that everybody’s gonna love,” she says. “The very, very last scene takes place in a place that we haven’t been to in a long time, and I think they will like seeing that.” Ultimately, though, Allen’s expectations for fans are simple.

“I think they’re gonna take away that they want ‘Grey’s Anatomy’ to go on another 10 years,” she says.

“Grey's Anatomy” 300th episode 8 p.m. Thursday on ABC