April Kepner's three sisters arrive in Seattle to attend her wedding on the next episode of Grey's Anatomy, titled Man on the Moon.

The three siblings will be played by Days of Our Lives' Emily Happe, Drop Dead Diva's Elizabeth Bond and The Middle's Grace Bannon, TVLine reported. 

The synopsis for the next episode reads: "April's [Sarah Drew] sisters arrive to help celebrate April's upcoming nuptials and quickly get on her nerves. Matthew [Justin Bruening] and Jackson [Jesse Williams] are forced to work together when they witness a terrible accident, Callie [Sara Ramirez] and Arizona [Jessica Capshaw] work hard to reestablish their relationship and Cristina [Sandra Oh] is pressured to live stream an upcoming surgery. Meanwhile, a familiar face returns to the hospital, on Grey's Anatomy."

Man on the Moon airs Thursday, Dec. 5 at 9 p.m. on ABC.

April told Jackson (Jesse Williams) in the Nov. 21 episode that she wants his blessing before she married Matthew. He gives her his blessing, then disinvites himself from the wedding. His actions raise Stephanie's (Jerrika Hinton) suspicions: she is wondering why the exes act strange around each other if they supposedly no longer in love.

After the medical drama's 12th episode this season, Grey's Anatomy will go on a winter hiatus and return Feb. 27 with another 12 episodes in a row. The cast is filming the mid-season finale on location, cast member Jerrika Hinton tweeted, without revealing the specific location. 

Leading up to Sandra Oh's exit from the show, episode 13 will feature flashbacks and a trip down memory lane for Derek (Patrick Dempsey) and Meredith (Ellen Pompeo), according to E! Online.

Tags: greys anatomy