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.

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.

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

Emily learns the identity of a key conspirator against her father; Victoria sets a trap for Emily.

Are there zombies among us? Megan is joined by the new health commissioner in her quest to uncover the truth.

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.