Complex sentence: With the help of Preacher Simms (John Carradine), a bible-quoting bounty hunter, Cain systematically tracks down and kills all of the men except Ameson, who is captured by Union soldiers and executed by firing squad before Cain can exact his revenge.
Split into simpler sentences: With the help of Preacher Simms (John Carradine), a bible-quoting bounty hunter, Cain systematically tracks down and kills the men. Cain is then frustrated in his attempt to kill Ameson, the last member of the gang, because Ameson is captured by Union soldiers and executed by firing squad before Cain can exact his revenge.