This episode is properly titled 'Ordeal' because a little trip for Lucas and Mark goes everything but right.
Starts out while Lucas and Mark have traveled to the desert to dig for salt for storing meat for the winter. A rattlesnake spooks the horse with the wagon and as Lucas tries to stop the runaway wagon he gets thrown off against a rock hurting his ribs. One of the horses breaks his leg and they are left with one horse and no wagon. With Lucas's ribs hurt, he does not let on to Mark just how injured he is and the start for home in they arid desert.
Next during a windstorm their only horse breaks away and runs off leaving Mark and Lucas stranded without an animal with only their water canteen. Then while climbing a rocky hill, a boulder comes loose hitting Lucas square in the foot. Just nothing is going right.
Lucas makes the decision to sent Mark for help. He loads Mark up with the rest of the water and tells him which way to walk. --But that is not all. There is even more ordeals in this unlucky show that come to Mark and Lucas in the unforgiving desert.
Not that it was a bad watch but I will say that the production company saved money with this episode. With all the scenes in one small area and only two other people appearing in the show for a total of one minute, this could have been filmed in one day. With that said, it was still a typical 'Rifleman' episode which is nearly always worth watching.