John Prosky

Izzie seems to be getting over Alex when she shares an undeniable chemistry with Denny Duquette, a patient who's awaiting a heart transplant, and George treats Bex, a young teen hermaphrodite.

A body is found covered in scratches, leading the BAU to believe that the person responsible has a chronic skin disorder.

Jack begins closing in on the location where Teri and Kimberly are being held hostage. Meanwhile, Teri and Kimberly create a shock of their own as things get violent at the compound. Also, Senator Palmer's worst fears are realized when he uncovers just how far his campaign backers are willing to go to protect him.

Peggy is faced with Leviathan's fury as she tries to save Howard Stark -- and the world.

Violet looks to Sheldon for advice after a patient makes a chilling confession; Addison tries to hide her grief; Cooper and Charlotte adjust to their new life; Sam confronts Sheldon.

When the Lone Gunmen come to the air of Reyes and Doggett on a case involving Morris Fletcher and a super soldier, they are led on a quest to find Yves Adele Harlow.