Two Mules for Sister Sara is a 1970 Western film directed by Don Siegel and starring Clint Eastwood and Shirley MacLaine. The film takes place in Mexico in the late 1860s during the French intervention in Mexico. Hogan (Eastwood) is an American mercenary who is hired by the Mexican Juarista rebels to help them capture a French-held fort. On his way to the fort, he comes across Sister Sara (MacLaine), who is being attacked by a group of bandits. Hogan saves her and finds out that she is a nun on a secret mission for the Mexican rebels.
Sister Sara convinces Hogan to help her reach a remote village, which she claims is a sanctuary for her fellow nuns. Along the way, they face several challenges, including a river crossing, a run-in with French soldiers, and an attack by a group of bandits. Despite these obstacles, they develop a bond, and Hogan begins to question Sister Sara's true mission.
As they approach the village, Hogan discovers that the nuns are actually a group of prostitutes who have been hiding from the French army. Sister Sara's real name is Sara Pennington, and she is a former prostitute who has been helping these women. Hogan and Sister Sara team up to help the women escape from the village and get to safety.
The film features several action-packed scenes, including a thrilling battle at the French-held fort and a tense climax as Hogan and Sister Sara try to evade the French soldiers. The film's portrayal of Sister Sara as a strong and independent woman was praised by critics and was considered ahead of its time for a Western film. The chemistry between Eastwood and MacLaine was also a highlight of the film.