The U.S. is in a heightened state of alert because suspected terrorists have gone missing. Meanwhile, Bartlet struggles with the message that he wants to convey to his youngest daughter Zoey's (recurring guest star ELISABETH MOSS), graduating class at Georgetown University. C.J. must stop reporter Danny Concanon (Timothy Busfield) from filing a story. And Charlie decides whether or not to keep a romantic promise he made to Zoey when they were dating. Recurring guest star TAYE DIGGS ("Chicago," "How Stella Got Her Groove Back") appears as the new head of Zoey's Secret Service detail.

Rachael Leigh Cook (She s all That) blows the whistle on an old man beat-down, Halle Berry (Gothika, Catwoman) is denied entrance into her own movie premiere and Taye Diggs (Brown Sugar) gets a touchy-feely examination from Dr. Punk'd.

Sam finds himself in the midst of a dangerous house call; Pete and Addison decide to take their relationship to the next level; Violet enters a "friends with benefits" pact with Cooper.

Charlotte seeks Pete's help in treating her insomnia; Naomi goes on her first date since college; Cooper suspects that his patient's injuries aren't an accident; a patient asks Addison and Naomi to conceal her fertility from her husband.

The Wellness Center starts a "Dads-to-be" class, much to Charlotte's displeasure; Sam and Naomi struggle to figure out where their relationship is going; Addison is conflicted about her status in the dating world; Cooper begins a secret affair with one of his colleagues.

Season 1: TV Guide kicks off its list of the sexiest stars on TV in style, featuring LOST'S Yunjin Kim and PRIVATE PRACTICE's Taye Diggs!

TV Guide kicks off its list of the sexiest stars on TV in style, featuring Lost'S Yunjin Kim and Private Practice's Taye Diggs!

Does Taye Diggs still get recognized for his "Groove"?

Jeffrey Sykes (Taye Diggs) gives Ford Cole (Ray Liotta) inside information.

Taye Diggs and Anthony Anderson try to scare and rough up B-Rad.