It is some years since nuclear war destroyed civilisation. A group of people exist underground, clinging to a crude form of Christianity and dependent on food stolen from the Communes, where the rest of mankind lives under a political dictatorship. Led by a priest called Magnus, the "Chrishuns" await deliverance by the "Others", the legendary survivors of the true Church. Leo, a Jew turned "Chrishun", distrusts Magnus' high-handed leadership and is tempted to take over the priesthood for himself. But events move too fast for him: sickness breaks out among the "Chrishuns", and the soldiers of the dreaded General of the Communes surround their hide-out. It is at this point, when the survival of his people is in the balance, that Magnus triumphantly justifies his leadership. Or does he?