With only three weeks and four episodes remaining in the fifth season of Grey's Anatomy, the intensity is really gaining momentum. As Meredith and Derek's wedding day approaches, she receives a visit from her dad, while ailing Izzie also has a parent stop in.

Oh, and there's also some deadly violence on Thursday's episode, apparently. The unusual perpetrator of said acts in "No Good at Saying Sorry" puts Mer and the Chief at odds.

Check out the promo below and see what you think ...

[video url="http://www.greysanatomyinsider.com/videos/no-good-at-saying-sorry-promo/" title="No Good at Saying Sorry Promo"] [/video]

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