Below are five sneak previews of "These Ties That Bind," Thursday's all-new episode of Grey's Anatomy. From the looks of it, there's a lot going on at Seattle Grace this week.

In the clip below, Meredith's old friend Sadie (Melissa George) shows up unannounced at her door - to the dismay of both Cristina and Derek, who lament things afterward ...

[video url="http://www.tvfanatic.com/videos/how-good-a-friend-could-she-be/" title="How Good a Friend Could She Be?"] [/video]

Funny stuff. Follow the jump for a quartet of additional sneak previews, including a confrontation between Derek and Owen, and the arrival of Dr. Dixon (Mary McDonnell) ...

[video url="http://www.tvfanatic.com/videos/circling-the-drain/" title="Circling the Drain"] [/video]

[video url="http://www.tvfanatic.com/videos/shes-a-little-off/" title="She's a Little Off"] [/video]

[video url="http://www.tvfanatic.com/videos/dont-call-it-a-piggyback/" title="Don't Call it a Piggyback"] [/video]

[video url="http://www.tvfanatic.com/videos/i-cant-believe-youre-here/" title="I Can't Believe You're Here"] [/video]

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