What is the main conflict in The Story of Lucy Gault by William Trevor?

The Story of Lucy Gault starts on June 21, 1921. Ireland is in the midst of civil unrest and anti-English violence. On that night, there is an intrusion in Lahardane, the home of the well-to-do Gault family, when three boys attempt to burn the family home down. Captain Everand Gault shoots his rifle to scare them away but unintentionally wounds one of the boys, Horahan.