ABC has released a preview of next week's all-new episode of Grey's Anatomy. In the clip below from "I Will Follow You Into the Dark," Derek reaches his breaking point. No, he doesn't punch Mark in the face this time, but he does walk off the job ...

[video url="http://www.greysanatomyinsider.com/videos/i-will-follow-you-into-the-dark-sneak-preview/" title="I Will Follow You Into the Dark Sneak Preview"] [/video]

Don't worry, fans. Star Patrick Dempsey has already stated that he is not leaving the series, so McDreamy will go back to work eventually despite how shaken up he seems by recent failures. Follow the link for more promos, news and Grey's Anatomy spoilers!

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.