Shonda Rhimes, you have a lot of explaining to do. In episode 21 of “Grey’s Anatomy,” the creator of the hit ABC series killed off one of the show’s most beloved characters: McDreamy.

Derek Shepherd (Patrick Dempsey) died after getting into a stomach-churning car accident, which led him to be rushed to a nearby hospital. The mishap ironically occurred after Derek had saved the lives of four people who were injured during another accident. Unfortunately for Derek, the surgeons who handled his case weren’t qualified enough to save his life: They opted out of performing a computerized tomography (CT) scan, which could have prevented his death due to bleeding in the brain.

Meredith Grey (Ellen Pompeo) was forced to make the final decision about Derek’s fate after being informed of the events leading to her husband’s death: Was she to keep him on life support or “pull the plug”? McDreamy’s wife chose the latter.

“Derek, it’s OK. You go,” Meredith said, with tears streaming down her cheeks (and ours, too) as she said goodbye to the love of her life. “I’ll be fine.”

The creator of the medical drama will use episode 22 to explore the effects of Derek’s death. In a promotional video for next week’s installment titled “She’s Leaving Home,” viewers can get a bittersweet taste of how Rhimes plans to break the horrific news to the characters of “Grey’s Anatomy.”

“Derek is dead,” audiences can hear Meredith saying as she confirms Derek’s death to her husband’s friends and sister. The doctors of Grey Sloan Memorial Hospital are clearly shaken up by the devestating announcement. Even the strongest characters, such as Miranda Bailey (Chandra Wilson), are brought to tears.

“Nothing has rocked these doctors like the death of one of their own,” the episode 22 trailer says. The surgeons at Grey Sloan have endured their fair share of losses, from George (T.R. Knight) to Mark (Eric Dane) and Lexie (Chyler Leigh). But of all the deaths on “Grey’s Anatomy,” this is the one that will have the greatest effect on Meredith.

“Mommy, where are we going?” Meredith’s daughter asks her in the promo video.

“Away, sweetie,” she replies.

Will Meredith be leaving Seattle and Grey Sloan Memorial Hospital behind her after the death of Derek? Viewers can find out in a “Grey’s Anatomy” two-hour special Thursday, May 14. Meanwhile, they can tune in to the episode “She’s Leaving Home” on ABC Thursday, April 30, at 8 p.m. EDT.

(Correction: The article originally stated that Izzie Stevens [Katherine Heigl] had died. She did not.)