Grey’s Anatomy said goodbye to fan-favorite character Alex Karev on Thursday, two months after Justin Chambers announced his departure from the show.

Chambers’ final episode aired November 14, though he has been mentioned on the show since. In this week’s episode, Chambers does not appear on screen, but he lends his voice to a series of letters that explain to rest of the characters why he left.

Alex sends letters to his co-workers Meredith, Bailey, Richard, and even his wife, Jo, to explain that he left to be with his ex-wife, Izzie. Izzie, played by Katherine Heigl, hasn’t been on the show since season six, which was 10 years ago. She also did not physically appear in Thursday’s episode at all.

Alex explained that while trying to save Meredith’s job he called up Izzie for a letter of recommendation. The two then began talking, and Izzie revealed she used the frozen embryos her and Alex saved following her cancer diagnosis to have his children. So, Alex leaves his wife and job to be with his children. In the letter to his wife he said:

“I have a chance to make this family whole, and I just hope you love me back enough to let me take it. I need to give these kids the family you and I never had.”

Included with his wife’s letter are divorce papers and his stock in Grey Sloan.

The tearful episode is full of flashbacks of moments Karev shared with his friends and co-workers. The Grey’s Anatomy Twitter shared some featured clips:

The only remaining original cast members on ABC’s longest running drama are Ellen Pompeo, who plays Meredith; James Pickens Jr., who plays Richard Webber; and Chandra Wilson, who plays Miranda Bailey.

Grey’s showrunner Krista Vernoff tweeted her goodbye to Alex: