Regi Davis

While undergoing aggressive cancer treatment, Izzie focuses on planning Meredith and Derek's wedding; Callie's father visits; Owen seeks help with his PTSD.

All reassess their personal lives after witnessing a chance reunion between two long-lost lovers in the emergency room; Karev treats a troubled teen; Meredith shares her suspicions with Cristina.

Prentiss resigns, Hotch requests a transfer and Gideon goes missing, leaving the team three members short as they hunt a serial killer in Milwaukee, who kidnaps women from public places.

The gang heads to the Caribbean, where Frasier begins to question his new romance with Claire.

Michael is so smitten with Gob's girlfriend that he decides to let her know that Gob has been cheating on her, and Lucille tries to break up Buster and Lucille Austero.

Gibbs and McGee travel to Russia to safely escort home an NCIS computer engineer connected to classified intel, but their mission is compromised and they are forced to go off the grid while hunted by a Russian mercenary group.