The play centres around seven captains of the Irish Insurgent Army and members of the Council of Ireland in a time of insurrection in the future. MacDonagh played his part in the Easter Rising 1916 as a Commandant of the 2nd Battalion of the Dublin Brigade, at Jacob's biscuit factory, and as signatory to the Proclamation of the Irish Republic. He was later executed as one of the seven leaders of the Easter Rising.