'Grey's Anatomy': What Happened to Derek? (Exclusive Video)

Grey's Anatomy fans are gearing up for what has been described as "the episode America will never forget" on Thursday.

During the hourlong episode, Derek's (Patrick Dempsey) whereabouts finally will be explained, as the Seattle doc witnesses a horrible car crash and lends a hand to three kids. But not everything, as they say, goes as planned, when the car and the trio of kids — including one portrayed by Parenthood alum Savannah Paige Rae — bursts into flames. Will the explosion claim McDreamy's life? All that remains unclear — for now.

The episode, perhaps fittingly entitled "How to Save a Life" — a familiar anthem for Grey's fans — was written by showrunner Shonda Rhimes. It's the first episode Rhimes has written since the season-eight finale in which Chyler Leigh's Lexie was killed off; Kim Raver's Teddy was written out; and the stage was set for Mark's (Eric Dane) death.

Also not helping matters is the fact that the police showed up at Meredith (Ellen Pompeo) and Derek's McMansion in the closing moments of the most recent episode.

Watch the clip above, exclusive to The Hollywood Reporter, and hit the comments below with your thoughts. Are you worried about McDreamy?

Grey's Anatomy airs Thursdays at 8 p.m. on ABC.

Email: Lesley.Goldberg@THR.com
Twitter: @Snoodit