Maggie tells Meredith she's worried about Nathan, who seemed especially sad about his fiancee Megan that day, after seeing parents reunited with the daughter they'd given up for dead years ago. Meredith remembers that when Derek died, there was just one day when she didn't know where he was, and she was going crazy inside. 'I guess it's like that for Nathan every day,' she says. 'Yeah. You get him,' Maggie tells her. Watch this scene from Season 13, Episode 14, 'Back Where You Belong,' and don't miss Grey's Anatomy THURSDAYS 8|7c on ABC.