Meredith Grey (Ellen Pompeo) will find herself involved in more relationship drama in "Grey's Anatomy" season 14 as her boyfriend Nathan Riggs' (Martin Henderson) former love interest, Megan Hunt (Abigail Spencer), moves back into the picture.

According to "Grey's Anatomy" executive producer and star Debbie Allen, however, it is Meredith herself that will encourage Nathan to reconnect with Megan.

Allen told TV Guide, "They both had a similar experience [losing their partners], but now this experience for Nathan is not even possible for her. Derek [Patrick Dempsey] is not coming back. [Meredith] will be re-examining and figuring out what's important in her life and how she will move on emotionally."

A new actress will be playing Owen's (Kevin McKidd) long-lost sister, Megan. Bridget Regan was unable to come back to "Grey's Anatomy" because of scheduling conflicts with her project "The Last Ship." Spencer from "Mad Men" and "Suits" is coming in to replace her for season 14.

Megan went missing for 10 years for reasons that remain unclear, as Nathan and Owen have different versions of the story. What is known is that Megan boarded a helicopter that went missing when it flew through an unprotected airspace.

According to Nathan, the reason for the helicopter trip was that they had to transport a patient. As the patient was Megan's, Nathan reluctantly let her board the chopper, although he did try to talk her out of it.

Owen, on the other hand, said that Nathan was not even near the chopper when Megan boarded but was with another woman. Owen said Megan called him up earlier that day to tell him that Nathan cheated on her repeatedly and that she was getting on a chopper to get away from him.

"Grey's Anatomy" season 14 premieres on Thursday, Sept. 28, 8 p.m. EDT on ABC.