Stacy Keach’s performance highlights John Osborne’s play about Martin Luther, the 16th-century cleric whose theories led to Protestantism. Hans: Patrick Magee. Tetzel: Hugh Griffith. Von Eck: Robert Stephens. Cajetan: Alan Badel. Katherine: Judi Dench. Weinand: Leonard Rossiter. Directed by Guy Green., Edward Anhalt adapted the John Osborne play about the 16th-century German monk who became the leader of the Protestant Reformation.