Eastwood is Jed Cooper, a man who is almost lynched by a group of vigilantes who think he is a cattle thief.
He eventually gets out of jail and is invited to be a town marshal. He accepts the offer and vows to bring each vigilante to justice, which he does.
Pat Hingle is Judge Fenton, a man who believes in the law so much he will kill innocent people just to have justice. Charles McGraw is a Sheriff who really doesn't want to round up any vigilantes as they are mostly his friends.
The movie moves along briskly and never fails to entertain. Eastwood is the only one who could have played this role and given it the impact it has. The rest of the cast includes Alan Hale, Inger Stevens, Ed Begley, Bruce Dern, Dennis Hopper, Arlene Golonka, L. Q. Jones, and Joseph Sirola.