Frasier - Season 11 Episode 21 -

Frasier offers Charlotte a ride to the train station, as she is headed to Portland to give a speech at a businesswomen's convention. She seems evasive when he tries to make future plans, so he insists that she explain what is wrong. She tells him that she is moving back to Chicago in three weeks, and doesn't think they should keep seeing each other because it will just make saying goodbye more painful. Charlotte ends up missing her train as they talk.