After a wild wind storm destroys the Robinsons crops, the family must go on short rations supplemented by protein pills. No one is very happy about this, especially Dr. Smith, who swears he is going to drop dead of starvation. As it happens, the storm was no accident. It was caused by a crafty merchant who has landed on the planet and intends to do business with the Robinson family. By ruining their supply of food, he hopes that they will be more inclined to trade with him. The Robinsons, of course, are unaware of this.