at the end of the line

1. At the physical end of a route of travel, usually a bus or train route. You'll need the most expensive ticket if you're getting off at the end of the line. I must have dozed off on the subway because I got on and, all of a sudden, we were at the end of the line! Time to get off, sir—we're at the end of the line.

2. By extension, at the conclusion or final step of something. We're finally at the end of the line with this project—now, we just have to hand it in and pray for a good grade! If this is their best and final offer, I guess we're at the end of the line, huh? Regardless of how this championship series goes, I know I'm at the end of the line, after 16 years in the league.