Harrison Ford plays a cop protecting an Amish woman and her son after the son witnesses a murder that takes place in a Philadelphia train station. The Amish woman and her son are expecting a brief sojourn into the English world while waiting for a train to Baltimore. Rachel has lost her husband and is hoping she and her son can heal while visiting her sister's community. After Samuel visits the men's room and witnesses the murder of a policeman, mother and son visit the police station, where Samuel fingers a dirty cop as the perp. Now the good guys are in trouble.
Harrison's character, John Book, is a detective who tries to keep track of the young witness and keep him and his mother from being harmed. John is shot before he can return mother and son to their community. John spends a couple of days naked and delirious in Rachel's house under her care.
Once he is well, John is asked by Rachel's father Eli to help around the place. John's first job is cow milking at 4 A.M. He does okay with that after a fashion.
Speaking of fashion, the milking hat is an exquisite piece of finery obviously meant to humble the wearer. Though none of the hats in this movie come anywhere near the handsomeness of the fedora in Indiana Jones, the milking hat is in a class all its own. I guess the point of Amish hats is to prove useful to the wearer while evoking neither lust in the observer nor vanity in the wearer.
John Book himself fits in pretty well after a while. He has useful carpentry skills that wow the plain, simple Rachel and gain him some measure of respect among the Amish, even with Daniel, his rival for Rachel's affection.
John has a good relationship with Rachel's family until the fateful night of the thunderstorm when she lets him catch her bathing. He musters up the strength to resist temptation by keeping focused on his mission and the differences between their worlds. While fixing his car, John's resolve slips and he shows Rachel how to dance to music on his car radio. He's no Patrick Swayze, but Rachel's community doesn't seem to know about dancing, so he looks pretty good.
The gun becomes a problem when the dirty cops from the English world figure out how to track John down in the Amish world. All the dirty cops ended up dead and John had to leave because he'd brought so much violence to the community. I don't think John missed Rachel and Samuel half as much as he missed getting up at 4 A.M. to put on that beautiful milking cap to milk old Bessie.