Flashback (1990)

In 1989, clean-cut FBI man John Buckner is detailed to escort heavily-bearded Huey Walker back to jail for offenses dating back to his days as a celebrated hippie radical. After Walker dupes Buckner on the train he falls into the hands of a couple of well-meaning refugees from the 60's, the two men with apparently nothing in common find themselves on the run together. But appearances can be deceptive.