'Grey's Anatomy' Season 11 Spoilers: 'One Flight Down' Haunts Arizona

"There's got to be some rule people who have been in a plane crash can't work on one," Alex (Justin Chambers) says in a promo video for the upcoming episode of "Grey's Anatomy" Season 11 this Thursday on ABC.

In this episode, a plane crash in Seattle causes multiple casualties. The victims are brought to Seattle Grace Hospital, bringing back horrible memories for Meredith (Ellen Pompeo) and Arizona (Jessica Capshaw).

In Season 8, Meredith and Arizona were with Lexie (Chyler Leigh), Cristina (Sandra Oh), Derek (Partick Dempsey) and Mark (Eric Dane) and several others from Seattle Grace aboard a plane that crashed into the woods. Some of the doctors suffered fatal injuries, including Lexie, who was crushed by a piece of a plane, and Mark, who suffered internal damage that eventually killed him.

Meredith was not to hurt, but she witnessed the death of her sister and the scene of her husband's hand stuck in the wall of the plane. Arizona's leg was horribly injured, causing the bone to break. Her leg had to be amputated due to infection.

Both women—Meredith and Arizona—will be in a dark place in Episode 20, literally and figuratively, as they hide out in the supplies closet as victims are being rushed into the E.R., looking like they are suffering from PTSD, as they are unable to help out.

For Meredith though, it is not only the plane crash trauma that she needs to deal with. In Episode 19, she receives a phone call asking her about Derek's whereabouts. He never arrived at his meeting in Washington. She is now having to deal with the possibility that her husband is missing.

"If at 5 p.m. you haven't heard from him, you can panic," Bailey (Chandra Wilson) tells her stressed-out co-worker in the promo video for episode 20.

The synopsis for Episode 20 concludes with Owen (Kevin McKidd) and Amelia's (Caterina Scorsone) breakup that will make for an "uncomfortable working situation for Stephanie (Jerrika Hinton)."

Episode 20 of "Grey's Anatomy" will air on Thursday, April 16, at 8 PM EDT on ABC.