The cast and creative team of Grey's Anatomy celebrated their milestone 200th episode with a party on Sept. 28 and revealed some details about upcoming storylines.

Episode 4 of season 10 marks the series' 200th episode, scheduled to air Oct. 10. Jessica Capshaw, who plays Arizona Robbins, told Entertainment Weekly the respective episode revolves around a big fundraising gala that will force the doctors to get all dressed up and the interns will be tasked with running the ER while the rest of the doctors are busy. Talking about what happens to her character in specific, Capshaw said fans will be surprised.

"The storyline actually takes an interesting and unexpected turn in the 200th episode for Arizona, and I think it's going to be funny," she said.

'Grey's Anatomy' Season 10 Spoilers: Cristina Yang's Exit Already Planned Out,

Fancy parties in past Grey's Anatomy episodes were sometimes filled with major heartbreak, such as Denny Duquette's death, but show creator Shonda Rhimes said this one will be a complete celebration.

"I think we really wanted to play the joy of the medicine and the joy of our character's journeys," she said. "And really, it's the first episode that Meredith Grey has really come back to work [after giving birth]. So we wanted to play some of the joy of that as well."

Viewers can also expect to see possible new hookups.

"I'm just going to say, if you're going to a fancy party on Grey's, you better watch yourself because you never know what's going to happen," said executive producer Betsy Beers. "There are some interesting combinations of people who are going to start to get together and get a little closer and it's a really, really different kind of party. You haven't seen a party like this before."

Rhimes said in a May interview that season 9 was the "season of romance" but that season 10 will be the "season of break-ups." The season 10 premiere already proved it to be correct, as Callie Torres moved out of the home she shared with Arizona and took with her their daughter. The former discovered that Arizona cheated on her by sleeping with a doctor visiting Grey-Sloan Memorial Hospital.

Scroll down for a promotional video for the Oct. 3 episode, Everybody's Crying Mercy, below. Its offical synopsis is as follows:

"Meredith and Derek adjust to life at home with a newborn but find it difficulty being away from the hospital; Arizona tries to takes steps to fix her broken marriage; Alex and Jo navigate through their new relationship; and Owen clashes with Jackson over financial issues at the hospital. Meanwhile, April anxiously awaits her boards results."

Grey's Anatomy airs Thursdays on ABC at 9 p.m. ET.

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