Yang is back....Meredith is happy, on Grey's Anatomy

The sadness was not over on Grey's Anatomy, for the characters who experienced the plane crash and lost family members, lovers and friends. At least it brought Cristina Yang back to Seattle.

Grey's Anatomy's creator Shonda Rhimes has knocked off characters right and left during the run of the show.

Last night, someone else had to die to get Cristina Yang to return to Seattle Grace, but it just seemed forced.

Her senior citizen doctor-mentor was in the midst of a surgery, assisted by Yang but he never made it through. Dr. Thomas had a massive attack, either a stroke or heart attack and dropped dead on the operating room floor.

Cristina was left to keep a young woman alive without assistance, while others in the OR tried to resuscitate Thomas She was successful despite her lover and direct superior Dr. Parker having warned her not to try it, even at the side of her mentor.

Dr. Thomas was being pushed out the door of the Mayo Clinic. His crime: too old, too slow, not ready for new methods, etc. One point made by Dr. Parker was valid.

He warned that the old timer could be dangerous to a patient's health. Parker didn't want him to perform the surgery, even with cracker jack Yang at his side. It wasn't for lack of competence however, he turned out to be a liability because of his advanced age and health.

In one of the final talks Cristina had with Thomas, he told her that no one has loved him, in a non-romantic way, as much as Yang in a very long time.

He praised her, told her not to compromise her talents to keep from showing anyone up. She was unique, in his opinion, among the younger crop of surgeons.

While hypothesizing about what life would be like if he left his job, Dr. Thomas upset Cristina. She told him pointedly that she couldn't work there without him. That is how important he became to her.

Yang has craved a mentor all along. Her first two got swept up in personal situations with her that ended badly. She was lost after her fiance' Dr. Burke exited her life.

She came back to life with Teddy Altman on the scene, until her relationship with Cristina's husband ultimately led to Altman's departure from Seattle.

To have lost Dr. Thomas, someone who loved her unconditionally and praised what Yang prizes most, her talent, was too much to bear alone in the freezing cold of Minnesota.

Meredith went through her own hellish experience in the episode, channeling her grief over the death of Lexie into saving a young woman from a similar fate. She found herself unable to be a working mom without proper help to be so single-minded about her work.

Cristina Yang showed up at Meredith's door high as a kite, thanks to tranquilizers that enabled her to get on an airplane to come home. The girls are back together and that's a good thing for us too.

Grey's Anatomy airs new episodes each Thursday at 9:00 p.m. ET/PT on ABC. Image: ABC Wikimedia Commons, Sandra Oh at a Writers Guild protest, 2007/Luke Ford