Mac Brandt

"Grey's Anatomy's" three-episode story arc continues with a part two that will challenge the interns of Seattle Grace -- and "Grey's" fans as well -- like never before.

Cristina, back from her honeymoon trip, searches in vain for Burke; Meredith, Cristina, Izzie and Alex spend their first day as residents with their own groups of interns.

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

Derek and Meredith get ready for their wedding; college students injured in a car accident are admitted to the ER; Izzie starts experiencing familiar symptoms.

The Feds call in Bell and Stabler when they suspect a gruesome murder could be connected to a string of bank robberies; when a DNA match is tied to a suspect with the perfect alibi, the team struggles to make a case against him.

Nick, Hank and Wu are called to the scene of the crime where a man claims his friend was consumed by a tree-like figure.