The story of the film Live by Night starts in 1926 .
In the 1920s , Joe Coughlin ( Ben Affleck ) , a World War I veteran of Irish descent and the prodigal son of Boston police captain Thomas Coughlin ( Brendan Gleeson ) , falls in love with Emma Gould ( Sienna Miller ) , the mistress of notorious gangster
Live by Night -LRB-film-RRB-