Below is a funny sneak preview of "The Heart of the Matter," the fourth episode of Season Four of Grey's Anatomy. Callie and Izzie are getting ready to throw down... and the meek George is caught in the middle. High noon at Seattle Grace!

[youtube]http://www.youtube.com/watch?v=d2WcJDE7YOw[/youtube]

Follow the jump for another sneak peak - an intense clip in which a head trauma patient's father becomes abusive and Derek tells Cristina she has to avoid that exact behavior herself and do better at the teaching facet of being a resident ...

[youtube]http://www.youtube.com/watch?v=ayPi1I6SRCI[/youtube]

Looks like a good one. Check out our episode main page for "The Heart of the Matter" for links to more previews and photos from Thursday's episode (our episode guide and quotes will also appear there after the show airs). You can also discuss it (and everything Grey's Anatomy) in our forum, as always!

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