Erica Hahn meets the men of Seattle Grace, while Izzie and Cristina clamor for her affections in "Kung Fu Fighting." Cool two-minute Grey's Anatomy video clip here.

A short ABC promo for "Physical Attraction, Chemical Reaction," the seventh episode of Season Four of Grey's Anatomy. Looks like a lot to keep track of in this one!

Meredith hears commotion outside her bedroom door and sees Alex getting it on with Lexie. Awkwardness ensues for Lexie and Meredith. Alex? He's cool.

A sneak preview of Grey's Anatomy episode 4.07, "Physical Attraction, Chemical Reaction." Cristina lectures Lexie about not talking about her personal life, when a baby and her mother both arrive in need of urgent care.

A sneak preview of episode seven of season four of Grey's Anatomy, entitled "Physical Attraction, Chemical Reaction." Meredith and Alex discuss his hooking up with Lexie. George and Izzie confide in Mer about sex with the other.

In this clip from "Forever Young," Dr. Bailey lets her charges know that she's back in command. No more fooling around. Grow up, Dr. Stevens!

In this preview clip from "Forever Young," a school bus crash leaves many patients at Seattle Grace... one of whom Derek Shepherd and his resident understudies must do everything they can to treat (and keep calm).

A slightly different promo for "Crash Into Me, Part II." Looks like a great episode coming up December 6.

Drs. Grey (older), Hahn and Stevens work frantically to save a patient trapped in an ambulance. Meredith tells Hahn to zip it! A sneak peak of "Crash Into Me, Part II."

The ABC promo for "Crash Into Me, Part II," the gripping conclusion of this two-part event from Season Four. It's not to be missed.

Patrick Dempsey on Good Morning America in November of 2007. The leading man of Grey's Anatomy and Enchanted talked about his work on both projects and was as dashing as we've come to expect.

Michael Phelps is coming to Grey's Anatomy. Not really. But this skit from Jimmy Kimmel would imply as much.