Maryanne makes a detour Interrupted Bridal Journey

Maryanne had been raised by her aunt, somewhat reclusively. Without any male suitors even knowing about her, let alone showing any interest, she decides to offer herself as a mail-order bride. 
 
Thomas is a successful businessman on the other side of the country, who up to now has had no inclination to get married. He now feels the need, however, and contacts a mail-order bridal agency. Upon receiving details of Maryanne from the agency, he writes to her and makes an offer of marriage. 
 
Maryanne finds Thomas's letters dull and devoid of any spark, but at the urging of her aunt, decides to accept his offer anyway. 
 
She boards the train to travel to San Francisco to join him, on which she meets a couple who happen to know Thomas. She extracts from them, more by omission than anything else, the fact that Thomas really is rather staid. 
 
Into the mix is thrown a soldier, Peter, who arrives in Maryanne's compartment abruptly during a Shawnee ambush. They are immediately attracted to each other, and after a whirlwind romance aboard the train, with Peter showing her various things outside her experience, including taking her onto the roof of a car, which then goes through a tunnel, he proposes to her, and she accepts, all the while understanding that Peter will not be able to provide for her nearly as well as Thomas would have been able. But she thinks that love will find a way.  
 
She and Thomas get married and set up home in Omaha, and seem blissfully happy. Maryanne falls pregnant, and she feels that things cannot get any better. 
 
However, will love really find a way? Will Peter carry on his loving ways once a baby arrives? Will Thomas take all of this lying down?"