'Citizen' Hogan is a Irish Republican patriot with a price on his head, serving in Algiers, where he is highly respected by his Foreign Legionaire comrades. After receiving a telegram, he asks permission to go back to Ireland to settle a matter involving family honor by killing D'Arcy, a fortune-hunting opportunist who has turned British informer. Back in Ireland Lord Justice O'Brien, who has the unenviable reputation of being a hanging judge and is haunted with self-doubt, is terminally ill and close to death. He tries to ensure his daughter Connaught's future welfare by coercing her to renounce her love for the upstanding but poor Dermot McDermot and marry the despicably unscrupulous but affluent D'Arcy, the man Hogan has returned to murder.