A doctor and a nun are both on the same train going west in 1905. The doctor is watching the nun. He is a young surgeon. The train stops in the desert. The doctor gets off the train. There is no shade. There are a bunch of laborers huddled around a man on the ground. The Mexican man is in pain. The foreman insists that the Mexican man, Pancho, is lying about being ill. The doctor insists that he should check him out. The Mexicans who are friends with Pancho are nervous and due to a language barrier, are unable to communicate with the surgeon about what is going on. 

The doctor examines Pancho and realizes that he is suffering from acute appendicitis and will likely die without emergency surgery. However, even with the surgery, Pancho may still die given the dire condition that he is in. The surgeon says he can do the surgery. The foreman is angry and ignorant. He is stubborn about the idea of the surgeon saving his worker. The other laborers become curious about what is going on. The surgeon becomes angry and swears. He condescends to the foreman by using big terms and name-dropping authority figures. He says the foreman will get in serious trouble for his negligence. The foreman communicates what the surgeon wants to do, however, he does it dramatically, portraying the surgeon’s intentions negatively. The surgeon and the foreman argue until the young surgeon goes back to the train. 

Yet, the surgeon has not given up. He knows he must find a way to perform the surgery and save the man’s life. He approaches the nun and asks if she has any hospital experience. She does. The surgeon explains the situation and the nun agrees that they will help the man together. The surgeon is impressed by the holy woman’s responsibility for life. They ask the train conductor if the train can wait for them to save the man. The train will not wait. 

The nun and surgeon get off the train, hoping it will remain delayed long enough for them to perform the surgery. Otherwise, they will have to wait until the train comes tomorrow, and if Pancho dies, the laborers may kill them. 

The surgeon exclaims that he wishes he never would’ve seen the sick man because now he has to save him. He says the Mexican means nothing to him and that no life is personal to a doctor, but he is responsible for preserving life. The nun appears annoyed at his outburst and utterance. 

The heat is almost unbearable as the two get off the train. The laborers are angry. Pancho looks even worse now. However, when they see the sister, they cross themselves and are quieter. She tells the foreman that the surgeon says he needs to do surgery. The foreman eventually agrees to translate the procedure for the Mexicans from the surgeon. The workers will not let the surgeon and nun operate on Pancho on the train. So, the pair will operate on him in a shed nearby. The foreman says that the Latino laborers will kill them if the surgery kills Pancho. The surgeon demands the pistol from the foreman.

They move Pancho into the shed and the surgeon prepares for the procedure. He has everything in his work bag that he needs. He is concerned about the state of the operating conditions, however, he knows Pancho will die otherwise. He performs the operation and is helped steadily and impressively by the nun. They hear the train move away as it is no longer delayed. They will have to sleep overnight. The surgery goes smoothly. The nun prays and the surgeon thinks about how her work for human life and the soul is important. The workers are waiting angrily outside in anticipation. The foreman fires his gun to calm them down and comes in and demands to see if Pancho is alive, which he is. 

They spend the night and wait for the next train in the morning. Pancho survives the night. The nun and the surgeon take Pancho with them into town to a hospital on the train. As the train drives away, the foreman shoots the train in a final display of his ignorance. They arrive safely in the town.