Task: Question Answering
Input (English): Passage: Katie Armstrong is a young widow and mother of three children - Charlie, Abner and Zoe. She is also engaged to be married to botany professor Grant Jordan. Grant is seeking funds to raise a new botany research building on the university campus where he works, and the most influential person to convince in this quest is his chancellor, Richard Fenster. Grant used to be involved with the chancellor's daughter, Minna, and is surprised when Minna crashes his bachelor party. Minna also almost succeeds in completely ruining Katie's engagement party. When Katie hears about Minna's visit at the bachelor party, Grant does his best to assure her that Minna is a finished chapter in his book, but he also has a hard time completely ignoring her, since he needs to be on good terms with the chancellor himself.
Minna is obviously out to sabotage the relationship between Grant and Katie. While the couple are to get married and go away on honeymoon, Katie's sister Jo has agreed to look after the children. Right before the wedding, Jo injures herself in a domestic accident, preventing her from fulfilling her promise to look after the children. The newly wed couple have no other alternative than to bring the children with them on their honeymoon. This is where things start going wrong. Abner and Charlie abandon the train they're riding together, and disappear into the night at the stop in Porterville. When the rest of the family arrive at Junction City, they take a taxi back to Porterville to look for the missing brothers. In Porterville they find out that the brothers have left for Junction City with a traveling salesman. It soon turns out they never made it all the way, but hitched with a local farmer, Mr. Webb, to his home. The family is finally reunited and the next day they board a train bound for the Grand Canyon. 
Question: What two children went missing during Grant and Katie's honeymoon?
Output (English): Abner.