An historical novel set in the last fort held by the Gaeil in Ulster. In 1651, Eoghan Rua Ó Néill is dead and Cromwell's army has swept the country. In Ulster, a small band of Gaeil under Féilim Ó Néill stand alone. They fortify Mountcharles Fort against the English. Before long they are surrounded by the English and their artillery is trained against the Gaelic garrison.