Episode 21 of "Grey's Anatomy," "How to Save a Life," will reveal Dr. Derek Shepherd's whereabouts, but his fate is still unknown, especially in light of recent news that actor Patrick Dempsey, who plays Derek, will exit the show because his "diva" behavior on the set has infuriated creator Shonda Rhimes, reports Page Six.

"Patrick has been acting like a diva and has clashed with Shonda. She suspended him for a while, and the word on set is that he isn't coming back full time," a source told Page Six. "Given all the past problems with Katherine Heigl and Isaiah Washington, there is little tolerance on the show for troublesome talent."

Dempsey has also hinted at exiting the show previously, telling the Portland Press Herald in November 2014 that he was leaving the show "very soon."

McDreamy fans will have to wait for a formal announcement from the network about his exit. Until then, we can focus on what's happening with the on-screen marriage between Derek and Meredith Grey.

In April 16's Episode 20, "One Flight Down," Derek returned to Washington, D.C. where he has worked since November to meet with the president. He missed the meeting and did not check in with worried wife Meredith. She finally decided to call the police.

In Thursday's Episode 21, "How to Save a Life," Derek witnesses a terrible car crash. He does everything in his power to save the victims and keep them alive, but could his efforts endanger him? Rumors are swirling that may be the case, but we will have until Thursday to find out.

"Next Thursday, nothing can prepare you for what happens next. This is the episode America will never forget," explains the narrator on the promo clip as startling scenes of the car crash and its aftermath play.

There are only three "Grey's Anatomy" episodes remaining in Season 11: "She's Leaving Home" Episode 22 that airs on April 30 and "Time Stops" Episode 23, airing on May 7. The finale is scheduled for May 14.

What would you like to see happen between Derek and Meredith? Do you think Derek will die? Share your theories and thoughts in the comment section below.

Watch Episode 21 "How To Save A Life" of "Grey's Anatomy" on Thursday, April 23 at 8:00 p.m. EST on ABC.