Outlaws Robert Hightower (John Wayne), Pedro "Pete" and William "The Abaleine kid" (Harry Carey jr) prepare to rob a bank.They fill up their cantines and a water bag at a spring and enter an Arizona town called Welcome.They stop off at a man's home called Perly "Buck" Sweet (Ward Bond) where his wife (Mae Marsh)makes them some tea.The woman asks them if they have seen a wagon on their journey,as her and Buck's niece and husband are on their way from New Jerusalem.They say they haven't seen them.Buck tells them where the town's bank is and they prepare to go and rob it.As Buck puts on his waistcoat they see that he's wearing a sheriff's badge.They cautiously ride off and still go through with pulling off the robbery.They get away with the money but as the are about to ride off out of town,the deputies come running out of the office and shoot William off of his horse.Robert pulls him up onto the back of his and they get away.Buck and his men pursue them across the desert and Buck shoots their waterbag without them realising.With only water left in their cantines,they wander along to a water tower in Mojave but Buck has devised a plan.He's taken the train with his men and is dropping a few of his deputies off at each water tower in the area to try and capture them.
Predicting Buck's next tactic,Robert decides that they should double back to Terrapin tanks.As they head off,they are caught up in a major sandstorm and lose their horses.Despite this,they make it to the tanks but Robert discovers an abandoned wagon there.He returns to Pedro and William and tells them that there's a pregnant woman inside it who is on the verge of giving birth.She's no husband because he's disappeared for days after pursuing their thirsty horses and the water tanks are empty because he had blown them up with dynamite after finding that the water level was too low.Robert asks Pedro to go and help the woman deliver the baby because he was once married with kids.He agrees.As he helps her,Robert and William try to collect as much water as they can from cactus heads.The woman gives birth and asks to see all three of them in the wagon as she lay exhausted and drained.She thanks them for what they've done and asks them to be the godfathers to her son that she names after them.Robert William Pedro.As she slowly passes away,they promise her that they'll look after her son.They bury her and try to figure out how to look after a baby.They come across a book in the wagon that explains how to look after a baby.As well as some baby clothes,some milk and a bible.A couple of days later,with the baby's milk running low,and all the water from the cactus heads gone,they decide it's best to trek across the desert with the baby and head for New Jerusalem.
Sick of waiting for them at Apache Wells, Buck Sweet realises that the outlaws have predicted his next move and gone to Terrapin tanks.So he decides to set off with some men on their trail.He finds the empty wagon and finds some clothes that belonged to his niece.Jumping to the wrong conclusion,he believs that they have killed his niece and her husband and blown up the water tanks.
Robert, William and Pedro become weaker as they try and make it across the desert.Becoming weaker because of his wound,Willliam dies of exhaustion.With just two of them left,Pedro falls over and breaks his leg.He asks Robert to leave his gun for him so he can warn off the coyotes but really it's to kill himself to avoid slowly suffering in the sun baked heat.He wishes Robert a Merry Christmas for the next day and as Robert wanders off with the baby,he hears the gunshot go off that he knows Pedro has used on himself.
Exhausted and drained,Robert feels like he can't go any further but as he starts to hallucinate he imagines his two friends walking along with him,encouraging him to not give up.He finds a stray donkey (just like the Bible passage said) and makes it to New Jerusalem.He walks into the saloon with the baby as everyone is celebrating Christmas.Buck enters after him and tells him to put his hands up.But Robert collapses on the floor.
Sometime later,Robert is back in the town of Welcome,where Buck is holding him in his cell while he awaits his trial.Buck,his wife and the rest of the town have taken kindly to Robert after saving the baby.The judge sentences him to 20 years unless he hands over the custody of the baby to the great uncle and auntie (Buck and his wife). But Robert is adamant that he's not going to break his promise to the dying woman and accepts the sentence.Proving his worth to the judge and everyone else,Robert is sentenced to a year and one day on the condition that he returns for the baby,and is given a cordial farewell from the townsfolk as he goes off to jail.