Starring Clint Eastwood as mercenary gunfighter Hogan, TWO MULES FOR SISTER SARA opens with its star saving a naked women from being gang-raped. He's more than a little surprised when the attractive woman, Sister Sara (Shirley McLaine), dons a habit. It seems she's deeply committed to a group of Mexican revolutionaries fighting against the French. Hogan agrees to escort her to the camp, since he's interested in helping them attack the French garrison, if the money is right. As they travel, Hogan becomes a bit suspicious of the nun's fondness for cigar smoking and the odd shot of whiskey.