Grey's Anatomy Season 9 has aired its premiere episode Thursday night in the U.S. It is one of the most high-anticipated TV series this fall. After eight years, the remaining main characters of the series have become "friends" with its most avid followers. Many questions were raised when the series closed its eighth season. How are the characters doing after the tragic crash?

Spoiler alert. If you have not watched Grey's Anatomy Season 9 Episode 1, skip to the Twitter shout outs of the other viewers. Read the episode highlights at your own risk.

Grey's Anatomy Season 9 Episode 1 Highlights: "Going, going, gone"

- Mark Sloan is in coma. This is not the last episode that will feature Sloan, but this is the beginning of his farewell. Seeing Callie and Derek reflect upon his life can pack a lot of emotions in a short moment.

- A meaner and colder Meredith Grey is running the old Nazi Bailey show. The plane crash has clearly changed her.

- Cristina is working at a different hospital but keeps in touch with Meredith.

- Arizona is present. But something's missing. And the dialogues hint Callie may have something to do with a part of her that is now gone.

- Derek drops an instrument while operating. This Shepherd never drops anything in his operating room. Naturally, he walks out.

- Alex tries to leave. He gives Bailey a new nickname, BCB.

- Owen hires April back.

Grey's Anatomy has raised the bar for deeply emotional yet again. The drama is made heavier by all the yet-to-be-expressed sentiments within the characters' very core. They are all trying to move on. But viewers know the healing is not complete. This is reason enough to look forward to succeeding episodes this season.

Twitter users are reacting on the just-aired premiere of Grey's Anatomy Season 9. Here are some of the tweets:

@jordanrmain: Holding back tears the whole time while watching #greysanatomy so @cgreig15 doesn't think I'm a baby #somanytears

@hollyelizabeth3: I'm never going to recover from this. Thank you, Shonda. I'm drowning in ugly tears. #GreysAnatomy

@jambalayaval55: "@Meigan: Still a #GreysAnatomy fan after all these years...still feel sad like I'm friends with them when tragedy strikes." Agreed.