Admitting that this letter is officially the worst thing he's ever done, Karev begins his letter by telling his wife that he loves her. He tells her that she deserves more than a letter and what he's doing to her, but he has to tell her that he is still in love with Izzie. He relays the same thing he told Meredith; that he initially reached out to Izzie for Meredith's trial. But he explains that as they began speaking, it felt like they were "frozen in time," and naturally fell into their old rhythms. He admits that if it were just about being torn between two women, he would be able to walk away from Izzie. "But Izzie has my kids," he emphasises, telling her that he knows she understands what that means.
He explains that he needs to stay with his kids to give them the two-parent household that both he and Jo never had. "I wish getting what I always wanted didn't have to hurt you in the process," he says to her. He goes on to tell her that he's already signed divorce papers, leaving her everything, including his shares in Grey Sloan Memorial. "Thank you. I'm sorry. I don't know how to end this," he finishes his letter. "I don't want to. Goodbye."