In a small Eastern town in 1889, Mabel King tries desperately to obtain a loan to keep her father's soap factory in business.  To that end, she invites Clumhill, the banker, to see the factory for himself.  Mabel's father J.L. is aghast when he learns this news because the company no longer has the employees needed to run the factory.  Mabel suggests that she and Waldo, her fiancée, run the machinery so that Clumhill will believe that they are still in business.  The machinery runs amok, but Clumhill reports that King Soap removed an old spot from his hat, and consequently, he will renew their note if they can produce some orders before the old note comes due in three weeks.

Mabel is convinced that she will be a better salesperson than Waldo, and finally, J.L. agrees to allow her to go on the road.  Waldo, however, is concerned about the dangers of the road and surreptitiously follows her.  At her first stop out West, Mabel learns that the saloon is the biggest soap user in town and, in an effort to seem friendly, she gets drunk there.  A gunfight breaks out between cowboy Mike and rustler Cactus Jack, and before he is shot, Mike slips a phony bill of sale into Mabel's pocket.  Cactus Jack searches Mike's body for the bill of sale, which is proof of his nefarious deeds, and when he fails to find it, divines what happened and goes looking for Mabel.

In the meantime, Mabel resolves to create a demand for the soap by selling it door-to-door.  At one house, the Owen family asks her to dinner and then to stay the night, but when they learn that she is a traveling saleswoman, they decide to keep her apart from their oldest son Simon, because their daughter ran away with a traveling salesman.  As a practical joke, Homer, their youngest son, sets traps for Mabel.  She evades them, but members of Cactus Jack's gang, who are trying to retrieve the bill of sale, are thwarted by them.

Later, when Mabel prepares for bed, she discovers the phony bill of sale, but does not understand its significance.  The following morning, the gunmen spot a group of Indians on the horizon and decide to let them dispose of Mabel.  Their plan fails when the Indian chief, the notorious Running Deer, spares Mabel's life after she accidentally eats a bar of soap and blows bubbles.

In the next town, Waldo waits anxiously for Mabel.  There, a store owner decides to create a demand for his surplus soap by starting a rumor that there is a diamond in one of the boxes.  Mabel hears the rumor, and believing that it is her father's ring, buys all the soap herself.

Later, the town is warned that the Indians are on the war path, and Mabel offers to intercede with Running Deer if everyone in town will agree to buy King Soap.  Cactus Jack and his cohorts then dress up as Indians, planning to kill Mabel and blame her death on them.  She is saved by the arrival of the real Indians, and after the townspeople recognize Cactus Jack, Mabel displays the bill of sale, and Cactus Jack is arrested.  Then Running Deer vows to remain peaceful if the town supplies him with King Soap, the only thing that can cure his itchy scalp.  Now that the factory is saved, Mabel and Waldo return home.