Burning Grey's Anatomy questions: Why is Izzie falling behind at work? Where's McDreamy? Is Mark more pathetic than Callie? Can Owen save a seizing teen's life with seconds to spare?

Here's a preview for tomorrow night's episode, "I Will Follow You Into the Dark," in which the first of those questions is posed by Cristina (and Richard wants to know where Derek is):

[video url="http://www.greysanatomyinsider.com/videos/i-will-follow-you-into-the-dark-sneak-preview-2/" title="I Will Follow You Into the Dark Sneak Preview #2"][/video]

For two more previews from Thursday's episode and lots more speculation on all the goings on at Seattle Grace, follow the link for copious quantities of Grey's Anatomy spoilers ...

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