Katherine Heigl will return to "Grey's Anatomy"

Katherine Heigl, who plays Dr. Isobel Stevens on ABC's hit drama, "Grey's Anatomy," has signed a contract for the sixth season of the show, E! Online reported.

This news follows another report that T. R. Knight, who plays George O'Malley on the show, will not be joining the cast for another season.

The season ended on a real cliffhanger, when both their characters were on the verge of death, and their fate remained unknown. Heigl's character was battling stage IV metastatic melanoma, underwent successful brain surgery, suffered from short term memory loss and flatlined during the last moments of the show.

Knight's character, on the other hand, was stuck by a bus in a surprise ending.

There were rumors that Heigl wanted to quit the show to focus on her film career, but her statements made it clear that she wasn't ready to go just yet. T. R. Knight too, seemed to have wanted to quit the show.